UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D. C. 20549  FORM N-CSRS  Investment Company Act file number  811-06071  DWS Institutional Funds (Exact Name of Registrant as Specified in Charter)  345 Park Avenue New York, NY 10154-0004 (Address of principal executive offices)             (Zip code)  Registrants Telephone Number, including Area Code:(212) 454-7190  Paul Schubert 345 Park Avenue New York, NY 10154-0004 (Name and Address of Agent for Service)  Date of fiscal year end:
        12/31
  Date of reporting period:
        06/30/08
   ITEM 1.REPORT TO STOCKHOLDERS   
 JUNE 30, 2008
Semiannual Report
to ShareholdersDWS Equity 500 Index Funde500pi_cover230 Contents click herePerformance Summary
click hereInformation About Your
Fund's Expenses
click herePortfolio Management
Review
click herePortfolio Summary
DWS Equity 500 Index Fund
click hereFinancial Statements
click hereFinancial Highlights
click hereNotes to Financial
Statements
DWS Equity 500 Index Portfolio
click hereInvestment Portfolio
click hereFinancial Statements
click hereFinancial Highlights
click hereNotes to Financial
Statements
click hereSummary of Management
Fee Evaluation by
Independent Fee Consultant
click hereAccount Management
Resources
click herePrivacy Statement This report must be preceded or accompanied by a prospectus. To obtain a
prospectus for any of our funds, refer to the Account Management Resources
information provided in the back of this booklet. We advise you to consider the
fund's objectives, risks, charges and expenses carefully before investing. The
prospectus contains this and other important information about the fund. Please
read the prospectus carefully before you invest. Investments in mutual funds involve risk. Some funds have more risk than others.
Derivatives may be more volatile and less liquid than traditional securities, and the
fund could suffer losses on its derivatives positions. This fund is not sponsored,
endorsed, sold, nor promoted by Standard & Poor's®, and Standard & Poor's makes no
representation regarding the advisability of investing in the portfolio. Additionally, the
fund may not be able to replicate the S&P 500® Index closely enough to track its
performance for several reasons, including the fund's cost to buy and sell securities,
the flow of money into and out of the fund and the potential underperformance of
stocks selected. Please read this fund's prospectus for specific information regarding
its investments and risk profile. DWS Investments is part of Deutsche Bank's Asset Management division and, within the
US, represents the retail asset management activities of Deutsche Bank AG, Deutsche Bank
Trust Company Americas, Deutsche Investment Management Americas Inc. and DWS Trust
Company. NOT FDIC/NCUA INSURED NO BANK GUARANTEE MAY LOSE VALUE
NOT A DEPOSIT NOT INSURED BY ANY FEDERAL GOVERNMENT AGENCY Performance SummaryJune 30, 2008 Institutional Class All performance shown is historical, assumes reinvestment of all dividend and
capital gain distributions, and does not guarantee future results. Investment
return and principal value fluctuate with changing market conditions so that,
when redeemed, shares may be worth more or less than their original cost.
Current performance may be lower or higher than the performance quoted.
Please visit www.dws-investments.com for the Fund's most recent month-end
performance. The total annual fund operating expense ratio, gross of any fee waivers or
expense reimbursements, as stated in the fee table of the prospectus dated
May 1, 2008 is 0.26% for Institutional Class shares. Please see the Information
About Your Fund's Expenses, the Financial Highlights and Notes to the Financial
Statements (Note C, Related Parties) sections of this report for gross and net
expense related disclosure for the period ended June 30, 2008. To discourage short-term trading, the Fund imposes a 2% redemption fee on
shareholders redeeming shares held less than 15 days, which has the effect of
lowering total return. Returns and rankings during all periods shown reflect a fee waiver and/or expense
reimbursement. Without this waiver/reimbursement, returns and rankings would have
been lower. Performance figures do not reflect the deduction of taxes that a shareholder would pay
on fund distributions or the redemption of fund shares. Returns and rankings may differ
by share class. Average Annual Total Returnsas of 6/30/08DWS Equity 500 Index Fund
6-Month
1-Year
3-Year
5-Year
10-YearInstitutional Class
-12.02%
-13.24%
4.33%
7.49%
2.79%S&P 500® Index+
-11.91%
-13.12%
4.41%
7.58%
2.88% Sources: Lipper Inc. and Deutsche Investment Management Americas Inc.   Total returns shown for periods less than one year are not annualized.  Net Asset Value and Distribution InformationInstitutional
ClassNet Asset Value:
6/30/08
$     144.8612/31/07
$     166.22Distribution Information:
Six Months as of 6/30/08:Income Dividends
$     1.44 Institutional Class Lipper Rankings  S&P 500 Index Objective Funds
Categoryas of 6/30/08Period
Rank

Number of
Funds Tracked
Percentile
Ranking (%)1-Year
37
of
185
203-Year
21
of
171
125-Year
14
of
153
910-Year
8
of
78
8 Source: Lipper Inc. Rankings are historical and do not guarantee future results.Rankings are based on total returns with distributions reinvested. Rankings are for
Institutional Class shares; other share classes may vary. Growth of an Assumed $1,000,000 Investment[]DWS Equity 500 Index Fund  Institutional Class
[]S&P 500 Index+e500pi_g10k1e0Yearly periods ended June 30 Comparative Resultsas of 6/30/08DWS Equity 500 Index Fund
1-Year
3-Year
5-Year
10-YearInstitutional
Class
Growth of $1,000,000
$867,600
$1,135,600
$1,434,700
$1,316,500Average annual total return
-13.24%
4.33%
7.49%
2.79%S&P 500
Index+
Growth of $1,000,000
$868,800
$1,138,100
$1,441,300
$1,328,700Average annual total return
-13.12%
4.41%
7.58%
2.88% The growth of $1,000,000 is cumulative. The minimum initial investment for the Institutional Class is $1,000,000. +  The Standard & Poor's 500 (S&P 500) Index is an unmanaged, capitalization-weighted
index of 500 stocks. The index is designed to measure performance of the broad
domestic economy through changes in the aggregate market value of 500 stocks
representing all major industries. "Standard & Poor's," "S&P 500," "Standard & Poor's
500" and "500" are trademarks of The McGraw-Hill Companies Inc., and have been
licensed for use by the Fund's investment advisor. Index returns assume reinvestment
of dividends and, unlike Fund returns, do not reflect any fees or expenses. It is not
possible to invest directly into an index.  Class S Class S shares are generally not available to new investors except under certain
circumstances. (Please refer to the Fund's Statement of Additional Information.) All performance shown is historical, assumes reinvestment of all dividend and
capital gain distributions, and does not guarantee future results. Investment
return and principal value fluctuate with changing market conditions so that,
when redeemed, shares may be worth more or less than their original cost.
Current performance may be lower or higher than the performance quoted.
Please visit www.dws-investments.com for the Fund's most recent month-end
performance. The total annual fund operating expense ratio, gross of any fee waivers or
expense reimbursements, as stated in the fee table of the prospectus dated
May 1, 2008 is 0.33% for Class S shares. Please see the Information About Your
Fund's Expenses, the Financial Highlights and Notes to the Financial Statements
(Note C, Related Parties) sections of this report for gross and net expense related
disclosure for the period ended June 30, 2008. To discourage short-term trading, the Fund imposes a 2% redemption fee on
shareholders redeeming shares held less than 15 days, which has the effect of
lowering total return. Returns and rankings during all periods shown reflect a fee waiver and/or expense
reimbursement. Without this waiver/reimbursement, returns and rankings would have
been lower. Performance figures do not reflect the deduction of taxes that a shareholder would pay
on fund distributions or the redemption of fund shares. Returns and rankings may differ
by share class. On May 19, 2003, the Investment Class of the Fund was issued in conjunction with the
combination of Equity 500 Index Fund  Investment (the "Acquired fund") and the
Fund. The Acquired fund was, and the Fund is, a feeder fund investing all of its
investable assets in the same master portfolio, the DWS Equity 500 Index Portfolio.
Returns shown prior to May 19, 2003 are the actual returns of the Acquired fund and
for the period after May 19, 2003 are those of the Fund's Investment Class. On
October 20, 2006, Investment Class was renamed Class S. Average Annual Total Returnsas of 6/30/08DWS Equity 500 Index Fund
6-Month
1-Year
3-Year
5-Year
10-YearClass S
-12.06%
-13.32%
4.21%
7.35%
2.65%S&P 500 Index+
-11.91%
-13.12%
4.41%
7.58%
2.88% Sources: Lipper Inc. and Deutsche Investment Management Americas Inc.   Total returns shown for periods less than one year are not annualized.  Net Asset Value and Distribution InformationClass SNet Asset Value:
6/30/08
$     143.4312/31/07
$     164.58Distribution Information:
Six Months as of 6/30/08:Income Dividends
$     1.36 Class S Lipper Rankings  S&P 500 Index Objective Funds Categoryas of 6/30/08Period
Rank

Number of
Funds Tracked
Percentile
Ranking (%)1-Year
51
of
185
283-Year
39
of
171
225-Year
37
of
153
2510-Year
26
of
78
33 Source: Lipper Inc. Rankings are historical and do not guarantee future results.
Rankings are based on total return with distributions reinvested. Rankings are for
Class S shares; other share classes may vary. Growth of an Assumed $10,000 Investment[]DWS Equity 500 Index Fund  Class S
[]S&P 500 Index+e500pi_g10k1d0Yearly periods ended June 30 Comparative Resultsas of 6/30/08DWS Equity 500 Index Fund
1-Year
3-Year
5-Year
10-YearClass S
Growth of $10,000
$8,668
$11,317
$14,259
$12,992Average annual total return
-13.32%
4.21%
7.35%
2.65%S&P 500 Index+
Growth of $10,000
$8,688
$11,381
$14,413
$13,287Average annual total return
-13.12%
4.41%
7.58%
2.88% The growth of $10,000 is cumulative. +  The Standard & Poor's 500 (S&P 500) Index is an unmanaged, capitalization-weighted
index of 500 stocks. The index is designed to measure performance of the broad
domestic economy through changes in the aggregate market value of 500 stocks
representing all major industries. "Standard & Poor's," "S&P 500," "Standard & Poor's
500" and "500" are trademarks of The McGraw-Hill Companies Inc., and have been
licensed for use by the Fund's investment advisor. Index returns assume reinvestment
of dividends and, unlike Fund returns, do not reflect any fees or expenses. It is not
possible to invest directly into an index.  Information About Your Fund's Expenses As an investor of the Fund, you incur two types of costs: ongoing
expenses and transaction costs. Ongoing expenses include management
fees and other Fund expenses. Examples of transaction costs include
sales charges (loads), redemption fees and account maintenance fees,
which are not shown in this section. The following tables are intended to
help you understand your ongoing expenses (in dollars) of investing in the
Fund and to help you compare these expenses with the ongoing
expenses of investing in other mutual funds. In the most recent six-month
period, the Fund limited these expenses; had it not done so, expenses
would have been higher. The example in the table is based on an
investment of $1,000 invested at the beginning of the six-month period
and held for the entire period (January 1, 2008 to June 30, 2008). The tables illustrate your Fund's expenses in two ways: •    Actual Fund Return. This helps you estimate the actual dollar amount
of ongoing expenses (but not transaction costs) paid on a $1,000
investment in the Fund using the Fund's actual return during the
period. To estimate the expenses you paid over the period, simply
divide your account value by $1,000 (for example, an $8,600 account
value divided by $1,000 = 8.6), then multiply the result by the number
in the "Expenses Paid per $1,000" line under the share class you hold. •    Hypothetical 5% Fund Return. This helps you to compare your Fund's
ongoing expenses (but not transaction costs) with those of other
mutual funds using the Fund's actual expense ratio and a hypothetical
rate of return of 5% per year before expenses. Examples using a 5%
hypothetical fund return may be found in the shareholder reports of
other mutual funds. The hypothetical account values and expenses
may not be used to estimate the actual ending account balance or
expenses you paid for the period. Please note that the expenses shown in these tables are meant to
highlight your ongoing expenses only and do not reflect any transaction
costs. The "Expenses Paid per $1,000" line of the tables is useful in
comparing ongoing expenses only and will not help you determine the
relative total expense of owning different funds. An account maintenance
fee of $6.25 per quarter for Class S shares may apply for certain accounts
whose balances do not meet the applicable minimum initial investment.
This fee is not included in these tables. If it was, the estimate of
expenses paid for Class S shares during the period would be higher, and
account value during the period would be lower, by this amount. Expenses and Value of a $1,000 Investmentfor the six months ended June 30, 2008Actual Fund Return*
Class S
Institutional
ClassBeginning Account Value 1/1/08
$     1,000.00
$     1,000.00Ending Account Value 6/30/08
$     879.40
$     879.80Expenses Paid per $1,000**
$     .93
$     .47Hypothetical 5% Fund Return*
Class S
Institutional
ClassBeginning Account Value 1/1/08
$     1,000.00
$     1,000.00Ending Account Value 6/30/08
$     1,023.87
$     1,024.37Expenses Paid per $1,000**
$     1.01
$     .50 * Expenses include amounts allocated proportionally from the master portfolio.  ** Expenses are equal to the Fund's annualized expense ratio for each share class,
multiplied by the average account value over the period, multiplied by the number of
days in the most recent six-month period, then divided by 366.  Annualized Expense Ratios
Class S
Institutional
ClassDWS Equity 500 Index Fund
.20%
.10% For more information, please refer to the Fund's prospectuses. Portfolio Management Review In the following interview, a team of portfolio managers from the
fund's subadvisor, Northern Trust Investments, discusses the market
environment and DWS Equity 500 Index Fund's performance for the
six-month period ended June 30, 2008. The views expressed in the following discussion reflect those of the portfolio management
team only through the end of the period of the report as stated on the cover. The
management team's views are subject to change at any time based on market and other
conditions and should not be construed as a recommendation. Past performance is no
guarantee of future results. Q: How would you describe the market environment over the
last six months? A:The first half of 2008 was a period of considerable economic
uncertainty and significant turmoil throughout the capital markets.
In the last few months of 2007, what began as a correction in the
subprime housing market soon accelerated into the worst
financial crisis in decades, with profound implications for the
entire US economy and related effects on global markets and
economies. By early 2008, financial markets had become quite
risk-averse, as demonstrated by wider credit spreads, severe
dislocation in short-term credit markets, overall tightening of
financial conditions and a highly volatile equity market. As
mid-year 2008 approached, US markets were faced with
additional bad news, including capital and liquidity problems
experienced by major financial institutions, increased concern
about rising prices for energy and food, as well as rising
unemployment. Essentially all equity indices posted negative returns for this
period. The Russell 3000® Index, which is generally regarded as a
good indicator of the broad stock market, had a negative return of
-11.05% for the six months ended June 30, 2008.1 The large-cap
Russell 1000® Index posted a return of -11.20% for the six-month
period, while the small-cap Russell 2000® Index returned
-9.37%.2 Growth stocks generally performed somewhat better
than value stocks: the return of the Russell 1000® Growth Index
was -9.06%, compared with -13.57% for the Russell 1000®
Value Index.3 1 The Russell 3000 Index is an unmanaged index that measures the performance of the
3,000 largest US companies based on total market capitalization, which represents
approximately 98% of the investable US equity market.   Index returns assume reinvestment of dividends and, unlike fund returns, do not reflect
any fees or expenses. It is not possible to invest directly in an index.  2 The Russell 1000 Index is an unmanaged index that measures the performance of the
1,000 largest companies in the Russell 3000 Index, which represents approximately
92% of the total market capitalization of the Russell 3000 Index. The Russell 2000 Index
is an unmanaged index that measures the performance of the 2,000 smallest companies
in the Russell 3000 Index, which represents approximately 8% of the total market
capitalization of the Russell 3000 Index.  3 The Russell 1000 Growth Index is an unmanaged index that measures the performance
of those Russell 1000 companies with higher price-to-book ratios and higher forecasted
growth values, while the Russell 1000 Value Index is an unmanaged index that
measures the performance of those Russell 1000 companies with lower price-to-book
ratios and lower forecasted growth values.  The Standard & Poor's 500® (S&P 500) Index returned -11.91%
for this period. The only industry sectors within the S&P 500 with
positive returns for this period were energy, materials and utilities;
the weakest sector by far was financials.4 4 The Standard & Poor's 500 (S&P 500) Index is an unmanaged, capitalization-weighted
index of 500 stocks. The index is designed to measure performance of the broad
domestic economy through changes in the aggregate market value of 500 stocks
representing all major industries.   Index returns assume reinvestment of dividends and, unlike fund returns, do not reflect
any fees or expenses. It is not possible to invest directly in an index.  Q: How did the fund perform during this period? A:The fund's Institutional Class shares returned -12.02%. (Past
performance is no guarantee of future results. Please see pages
5 through 8 for the performance of other share classes and
more complete performance information.) Since the fund's
investment strategy is to replicate, as closely as possible, before
the deduction of expenses, the performance of the S&P 500
index, the fund's return is normally close to the return of the
index. Q: Which stocks had the greatest effect on performance? A:Since the index is weighted by market capitalization, the
largest stocks generally have the greatest impact on index
returns, even when other stocks have the highest or lowest
returns. The top two contributors, each of which has a weight of
more than 1% in the index, were Wal-Mart Stores, Inc. and
International Business Machines Corp. Many of the stocks that
contributed strongly to the return of the index were energy
companies; these include Devon Energy Corp., Halliburton Co.,
Chevron Corp. and Chesapeake Energy Corp. The greatest detractor from performance was General Electric
Co., which has a weight of more than 2% in the index. GE stock
dropped sharply on a disappointing earnings report and concerns
about troubled loans in the company's large consumer finance
unit. Most of the other strong detractors were in the financials
sector; these include American International Group, Inc., Bank of
America Corp. and Citigroup, Inc. Q: What changes were made in the S&P 500 Index during the
first half of 2008? A:Standard & Poor's adjusts the composition of the S&P 500 to
reflect changes in the relative size of companies and changes in
corporate ownership. Most changes result from merger and
acquisition activity, although some occur when a company is
delisted or shrinks to the point that it is moved to a different
index. Additions are selected from companies that have reached a
size that makes them appropriate for inclusion. During the first
six months of 2008, there were 10 additions and 10 deletions to
the index. Among the additions during the period were Philip Morris
International, Inc., which was spun off from index component
Altria Group, Inc.; Southwestern Energy Co.; Lorillard, Inc.; Cabot
Oil & Gas Corp.; and AK Steel Holding Corp. The list of deletions is dominated by troubled financial companies
that were acquired or dropped in market value below the level
appropriate for inclusion; these include The Bear Stearns
Companies, Inc., Ambac Financial Group and Countrywide
Financial Corp. Other deletions include Harrah's Entertainment,
which was taken private; Circuit City Stores, Inc.; Trane, Inc.,
OfficeMax, Inc.; and Brunswick Corp. Q: Do you have other comments for shareholders? A:We believe that holding an index fund such as this one can be
advantageous because it offers broad exposure to the equity
market at a relatively low cost. Portfolio Summary Asset Allocation(As a % of Investment Portfolio)
6/30/08
12/31/07Common Stocks
99%
99%Cash Equivalents
1%
1%100%
100% Sector Diversification(As a % of Common Stocks)
6/30/08
12/31/07Information Technology
17%
16%Energy
16%
13%Financials
14%
18%Health Care
12%
12%Industrials
11%
12%Consumer Staples
11%
10%Consumer Discretionary
8%
8%Utilities
4%
4%Materials
4%
3%Telecommunication Services
3%
4%100%
100% Asset allocation and sector diversification are subject to change. Ten Largest Equity Holdings at June 30, 2008(19.4% of Net Assets)1.      ExxonMobil Corp.
Explorer and producer of oil and gas
4.1%2.      General Electric Co.
Manufactures, distributes and markets electrical products
2.4%3.      Microsoft Corp.
Developer of computer software
2.0%4.      Chevron Corp.
Operator of petroleum exploration, delivery and refining facilities
1.8%5.      AT&T, Inc.
Provider of communications services
1.8%6.      Procter & Gamble Co.
Manufacturer of diversified consumer products
1.6%7.      Johnson & Johnson
Provider of health care products
1.6%8.      International Business Machines Corp.
Manufacturer of computers and provider of information processing services
1.5%9.      ConocoPhillips
Producer of petroleum and other natural gases
1.3%10.     Apple, Inc.
Manufacturer of personal computers and related personal computing and
communication solutions
1.3% Portfolio holdings are subject to change. For more complete details about the Portfolio's investment portfolio, see page 28. A
quarterly Fact Sheet is available upon request. Information concerning portfolio holdings of
the Portfolio as of month end will be posted to www.dws-investments.com on or after the
last day of the following month. In addition, the Portfolio's top ten holdings and other
information about the Fund is posted on www.dws-investments.com as of the calendar
quarter-end on or after the 15th day following quarter-end. Please see the Account
Management Resources section for contact information. Following the Fund's fiscal first and third quarter-end, a complete portfolio
holdings listing is filed with the SEC on Form N-Q. The form will be
available on the SEC's Web site at www.sec.gov, and it also may be
reviewed and copied at the SEC's Public Reference Room in Washington,
D.C. Information on the operation of the SEC's Public Reference Room
may be obtained by calling (800) SEC-0330. Financial Statements Statement of Assets and Liabilitiesas of June 30, 2008 (Unaudited)AssetsInvestment in the DWS Equity 500 Index Portfolio, at value
$       2,550,348,871Receivable for Fund shares sold
1,199,180Due from Advisor
279,138Other assets
34,921Total assets
2,551,862,110LiabilitiesPayable for Fund shares redeemed
3,009,306Accrued expenses and other payables
675,038Total liabilities
3,684,344Net assets, at value
$    2,548,177,766Net Assets Consist ofUndistributed net investment income
1,844,545Net unrealized appreciation (depreciation) on investments and futures
1,471,672,575Accumulated net realized gain (loss)
(218,765,505)Paid-in capital
1,293,426,151Net assets, at value
$    2,548,177,766Net Asset ValueClass S
Net Asset Value, offering and redemption price(a) per share
($688,413,870 ÷ 4,799,512 outstanding shares of beneficial interest,
$.01 par value, unlimited number of shares authorized)
$    143.43Institutional Class
Net Asset Value, offering and redemption price(a) per share
($1,859,763,896 ÷ 12,837,964 outstanding shares of beneficial interest,
$.01 par value, unlimited number of shares authorized)
$    144.86 (a)  Redemption price per share for shares held less than 15 days is equal to net asset value
less a 2% redemption fee.  The accompanying notes are an integral part of the financial statements. Statement of Operationsfor the six months ended June 30, 2008 (Unaudited)Investment IncomeIncome and expenses allocated from DWS Equity 500 Index Portfolio:Dividends
27,034,755Interest  Cash Management QP Trust
531,408Interest
35,064Expenses*
(653,945)Total Income
26,947,282Expenses:Administration fee
1,307,004Services to shareholders
612,441Professional fees
60,846Trustees' fees and expenses
19,307Reports to shareholders
47,280Registration fees
22,603Other
7,823Total expenses before expense reductions
2,077,304Expense reductions
(1,051,622)Total expenses after expense reductions
1,025,682Net investment income (loss)
25,921,600Realized and Unrealized Gain (Loss)Net realized gain (loss) allocated from DWS Equity 500 Index Portfolio:Investments
(2,548,145)Futures
(4,300,506)(6,848,651)Change in net unrealized appreciation (depreciation) allocated from DWS
Equity 500 Index Portfolio on:Investments
(353,449,370)Futures
(2,115,176)(355,564,546)Net gain (loss)
(362,413,197)Net increase (decrease) in net assets resulting from operations
$    (336,491,597) *  For the six months ended June 30, 2008, the DWS Equity 500 Index Portfolio was
reimbursed by the Advisor for fees in the amount of $717,529, of which $579,319 was
allocated to this Fund on a pro-rated basis.  The accompanying notes are an integral part of the financial statements. Statement of Changes in Net AssetsIncrease (Decrease) in Net Assets
Six Months
Ended June 30,
2008
(Unaudited)
Year Ended
December 31,
2007Operations:Net investment income (loss)
$       25,921,600
$       52,725,879Net realized gain (loss)
(6,848,651)
57,148,035Change in net unrealized appreciation (depreciation)
(355,564,546)
45,321,459Net increase (decrease) in net assets resulting from
operations
(336,491,597)
155,195,373Distributions to shareholders from:Net investment income:Class S
(6,414,045)
(14,337,230)Institutional Class
(17,780,229)
(38,315,257)Total distributions
(24,194,274)
(52,652,487)Fund share transactions:Proceeds from shares sold
366,547,937
544,258,985Reinvestment of distributions
23,132,785
50,353,547Cost of shares redeemed
(203,817,540)
(735,982,664)Redemption fees
11,188
14,697Net increase (decrease) in net assets from Fund share
transactions
185,874,370
(141,355,435)Increase (decrease) in net assets
(174,811,501)
(38,812,549)Net assets at beginning of period
2,722,989,267
2,761,801,816Net assets at end of period (includes undistributed net
investment income of $1,844,545 and $117,219,
respectively)
$    2,548,177,766
$    2,722,989,267 The accompanying notes are an integral part of the financial statements. Financial Highlights Class S+
Years Ended
December 31,
2008a
2007
2006
2005
2004
2003bSelected Per Share DataNet asset value,
beginning of period
$    164.58
$    158.94
$    139.85
$    135.69
$    124.93
$    106.22Income (loss) from
investment operations:
Net investment income
(loss)c
1.46
2.96
2.56
2.21
2.27
1.07Net realized and
unrealized gain (loss)
(21.25)
5.61
19.04
4.10
10.78
18.89Total from investment
operations
(19.79)
8.57
21.60
6.31
13.05
19.96Less distributions from:
Net investment income
(1.36)
(2.93)
(2.51)
(2.15)
(2.29)
(1.25)Redemption fees
.00***
.00***
.00***
.00***

Net asset value, end
of period
$    143.43
$    164.58
$    158.94
$    139.85
$    135.69
$    124.93Total Return (%)d
(12.06)**
5.39
15.58
4.70
10.57
18.88**Ratios to Average Net Assets and Supplemental DataNet assets, end of period
($ millions)
688
772
771
768
727
573Ratio of expenses before
expense reductions,
including expenses
allocated from DWS Equity
500 Index Portfolio (%)
.31*
.29
.33
.36
.36
.36*Ratio of expenses after
expense reductions,
including expenses
allocated from DWS Equity
500 Index Portfolio (%)
.20*
.19
.22
.25
.25
.25*Ratio of net investment
income (loss) (%)
1.91*
1.77
1.73
1.62
1.77
1.52*aFor the six months ended June 30, 2008 (Unaudited).bFor the period from May 19, 2003 (commencement of operations of Investment Class
shares) to December 31, 2003.cBased on average shares outstanding during period.dTotal return would have been lower had certain expenses not been reduced.+On October 20, 2006 Investment Class shares were renamed Class S shares.*Annualized**Not annualized***Amount is less than $.005. Institutional Class
Years Ended
December 31,
2008a
2007
2006
2005
2004
2003Selected Per Share DataNet asset value,
beginning of period
$    166.22
$    160.54
$    141.29
$    137.10
$    126.22
$    99.84Income (loss) from
investment operations:
Net investment income
(loss)b
1.54
3.11
2.73
2.41
2.46
1.85Net realized and
unrealized gain (loss)
(21.46)
5.71
19.28
4.16
10.93
26.33Total from investment
operations
(19.92)
8.82
22.01
6.57
13.39
28.18Less distributions from:
Net investment income
(1.44)
(3.14)
(2.76)
(2.38)
(2.51)
(1.80)Redemption fees
.00***
.00***
.00***
.00***

Net asset value, end
of period
$    144.86
$    166.22
$    160.54
$    141.29
$    137.10
$    126.22Total Return (%)c
(12.02)**
5.49
15.72
4.85
10.74
28.45Ratios to Average Net Assets and Supplemental DataNet assets, end of period
($ millions)
1,860
1,951
1,991
1,812
1,828
1,982Ratio of expenses before
expense reductions,
including expenses
allocated from DWS Equity
500 Index Portfolio (%)
.23*
.22
.20
.11
.11
.11Ratio of expenses after
expense reductions,
including expenses
allocated from DWS Equity
500 Index Portfolio (%)
.10*
.10
.10
.10
.10
.10Ratio of net investment
income (loss) (%)
2.01*
1.86
1.85
1.77
1.92
1.69aFor the six months ended June 30, 2008 (Unaudited).bBased on average shares outstanding during the period.cTotal return would have been lower had certain expenses not been reduced.*Annualized**Not annualized***Amount is less than $.005. Notes to Financial Statements(Unaudited) A. Significant Accounting Policies DWS Equity 500 Index Fund (the "Fund"), is a diversified series of DWS
Institutional Funds (the "Trust") which is registered under the Investment
Company Act of 1940, as amended, (the "1940 Act"), as an open-end
management investment company organized as a Massachusetts
business trust. The Fund, a feeder fund, seeks to achieve its investment objective by
investing all of its investable assets in a master portfolio, DWS Equity 500
Index Portfolio (the "Portfolio"), a diversified, open-end management
investment company advised by Deutsche Investment Management
Americas Inc. ("DIMA"), an indirect, wholly owned subsidiary of Deutsche
Bank AG. On June 30, 2008, the Fund owned approximately 81% of the
Portfolio. The Fund offers two classes of shares: Institutional Class and Class S.
Institutional Class and Class S shares are offered to a limited group of
investors, and are not subject to initial or contingent deferred sales
charges. Institutional shares have lower ongoing expenses than Class S
shares. Investment income, realized and unrealized gains and losses, and certain
fund-level expenses and expense reductions, if any, are borne pro rata on
the basis of relative net assets by the holders of both classes of shares,
except that each class bears certain expenses unique to that class such as
services to shareholders and certain other class specific expenses.
Differences in class-level expenses may result in payment of different per
share dividends by class. All shares of the Fund have equal rights with
respect to voting subject to class-specific arrangements. The Fund's financial statements are prepared in accordance with
accounting principles generally accepted in the United States of America
which require the use of management estimates. Actual results could
differ from those estimates. The policies described below are followed
consistently by the Fund in the preparation of its financial statements. The
financial statements of the Portfolio, including the Investment Portfolio,
are contained elsewhere in this report and should be read in conjunction
with the Fund's financial statements. Security Valuation. The Fund records its investment in the Portfolio at
value, which reflects its proportionate interest in the net assets of the
Portfolio. Valuation of the securities held by the Portfolio is discussed in
the notes to the Portfolio's financial statements included elsewhere in this
report. New Accounting Pronouncement. In March 2008, FASB issued
Statement of Financial Accounting Standards No. 161 ("FAS 161")
Disclosures about Derivative Instruments and Hedging Activities, an
amendment of FASB Statement No. 133. FAS 161 requires enhanced
disclosure about an entity's derivative and hedging activities. FAS 161 is
effective for fiscal years beginning after November 15, 2008. Management
is currently evaluating the impact the adoption of FAS 161 will have on the
Fund's financial statement disclosures. Federal Income Taxes. The Fund's policy is to comply with the
requirements of the Internal Revenue Code, as amended, which are
applicable to regulated investment companies, and to distribute all of its
taxable income to its shareholders. At December 31, 2007, the Fund had a net tax basis capital loss
carryforward of approximately $212,361,000, which may be applied
against any realized net taxable capital gains of each succeeding year
until fully utilized or until December 31, 2010 ($40,520,000),
December 31, 2011 ($53,713,000), December 31, 2012 ($73,803,000),
December 31, 2013 ($22,344,000) and December 31, 2014 ($21,981,000),
the respective expiration dates, whichever occurs first, which may be
subject to certain limitations under Sections 382-384 of the Internal
Revenue Code. The Fund has reviewed the tax positions for the open tax years as of
December 31, 2007, and has determined that no provision for income tax
is required in the Fund's financial statements. The Fund's federal tax
returns for the prior three fiscal years remain subject to examination by
the Internal Revenue Service. Distribution of Income and Gains. Net investment income of the Fund is
declared and distributed to shareholders quarterly. Net realized gains from
investment transactions, in excess of available capital loss carryforwards,
would be taxable to the Fund if not distributed, and, therefore, will be
distributed to shareholders at least annually. The timing and characterization of certain income and capital gains
distributions are determined annually in accordance with federal tax
regulations which may differ from accounting principles generally
accepted in the United States of America. As a result, net investment
income (loss) and net realized gain (loss) on investment transactions for a
reporting period may differ significantly from distributions during such
period. Accordingly, the Fund may periodically make reclassifications
among certain of its capital accounts without impacting the net asset
value of the Fund. The tax character of current year distributions will be determined at the
end of the current fiscal year. Redemption Fees. The Fund imposes a redemption fee of 2% of the total
redemption amount on the Fund shares redeemed or exchanged within 15
days of buying them, either by purchase or exchange. This fee is assessed
and retained by the Fund for the benefit of the remaining shareholders.
The redemption fee is accounted for as an addition to paid-in capital. Contingencies. In the normal course of business, the Fund may enter into
contracts with service providers that contain general indemnification
clauses. The Fund's maximum exposure under these arrangements is
unknown as this would involve future claims that may be made against
the Fund that have not yet been made. However, based on experience,
the Fund expects the risk of loss to be remote. Other. The Fund receives a daily allocation of the Portfolio's income,
expenses and net realized and unrealized gains and losses in proportion to
its investment in the Portfolio. Expenses directly attributed to a fund are
charged to that fund, while expenses which are attributable to the Trust
are allocated among the funds in the Trust on the basis of relative net
assets. B. Related Parties Deutsche Investment Management Americas Inc. ("DIMA" or the
"Advisor"), an indirect, wholly owned subsidiary of Deutsche Bank AG, is
the Advisor for the Portfolio. For Institutional Class shares, the Advisor has voluntarily agreed to waive
all or a portion of its fees and reimburse or pay certain operating expenses
of the Fund, including expenses allocated from the Portfolio (excluding
certain expenses such as extraordinary expenses, taxes, brokerage and
interest) to the extent necessary to maintain the operating expenses at
0.10%. This voluntary waiver of reimbursement may be terminated at any
time at the option of the Advisor. Under this arrangement, during the six months ended June 30, 2008,
DIMA waived $66,835 of sub-recordkeeping expenses for Institutional
Class shares. Administration Fee. Pursuant to an Administrative Services Agreement,
DIMA provides most administrative services to the Fund. For all services
provided under the Administrative Services Agreement, the Fund pays the
Advisor an annual fee ("Administration Fee") of 0.10% of the Fund's
average daily net assets, computed and accrued daily and payable
monthly. For the six months ended June 30, 2008, the Advisor received
an Administration Fee of $1,307,004, of which $815,359 was waived and
$91,936 is unpaid. Service Provider Fees. DWS Investments Service Company ("DISC"), an
affiliate of the Advisor, is the transfer agent, dividend-paying agent and
shareholder service agent for the Fund. Pursuant to a sub-transfer agency
agreement among DISC and DST Systems, Inc. ("DST"), DISC has
delegated certain transfer agent, dividend-paying agent and shareholder
service agent functions to DST. DISC compensates DST out of the
shareholder servicing fee it receives from the Fund. For the six months
ended June 30, 2008, the amount charged to the Fund by DISC was as
follows. Services to Shareholders
Total
Aggregated
Waived
Unpaid at
June 30, 2008Class S
$       38,157
$       
$       38,157Institutional Class
156,071
156,071
$    194,228
$    156,071
$    38,157 Typesetting and Filing Service Fees. Under an agreement with DIMA,
DIMA is compensated for providing typesetting and certain regulatory
filing services to the Fund. For the six months ended June 30, 2008, the
amount charged to the Fund by DIMA included in the Statement of
Operations under "reports to shareholders" aggregated $15,438, of which
$13,066 is unpaid. Trustees' Fees and Expenses. The Fund paid each Trustee not affiliated
with the Advisor retainer fees plus specified amounts for various
committee services and for the Board Chairperson and Vice Chairperson. In connection with the board consolidation on April 1, 2008 of the two
DWS Funds Boards of Trustees, certain Independent Board Members
retired prior to their normal retirement date, and received a one-time
retirement benefit. DIMA has agreed to reimburse the Funds for the cost
of this benefit. During the period ended June 30, 2008, the Fund paid its
allocated portion of the retirement benefit of $13,357 to the
non-continuing Independent Board Members, and the Fund was
reimbursed by DIMA for this payment. C. Share Transactions The following table summarizes share and dollar activity in the Fund: Six Months Ended June 30, 2008
Year Ended December 30, 2007Shares
Dollars
Shares
DollarsShares soldClass S
528,879
$       81,120,136
1,230,022
$       202,198,150Institutional Class
1,856,322
285,427,801
2,056,012
342,060,835$    366,547,937

$    544,258,985Shares issued to shareholders in reinvestment of distributionsClass S
40,351
$       6,030,755
80,585
$       13,391,131Institutional Class
113,315
17,102,030
220,197
36,962,416$    23,132,785

$    50,353,547Shares redeemedClass S
(461,941)
$       (70,618,957)
(1,470,504)
$       (241,973,067)Institutional Class
(867,789)
(133,198,583)
(2,939,413)
(494,009,597)$    (203,817,540)

$    (735,982,664)Redemption fees

$    11,188

$    14,697Net increase (decrease)Class S
107,289
$       16,537,502
(159,897)
$       (26,376,570)Institutional Class
1,101,848
169,336,868
(663,204)
(114,978,865)$    185,874,370

$    (141,355,435)  (The following financial statements of the
DWS Equity 500 Index Portfolio should be read in
conjunction with the Fund's financial statements.) Investment Portfolioas of June 30, 2008 (Unaudited) Shares
Value ($)Common Stocks 98.4%Consumer Discretionary 8.0%Auto Components 0.2%Goodyear Tire & Rubber Co.*
58,496
1,042,984Johnson Controls, Inc.
155,192
4,450,9065,493,890Automobiles 0.2%Ford Motor Co.*
625,176
3,007,097General Motors Corp.
168,171
1,933,966Harley-Davidson, Inc.
63,851
2,315,2377,256,300Distributors 0.1%Genuine Parts Co.
44,678
1,772,823Diversified Consumer Services 0.1%Apollo Group, Inc. "A"*
39,583
1,751,943H&R Block, Inc.
84,782
1,814,3353,566,278Hotels Restaurants & Leisure 1.2%Carnival Corp. (Unit)
120,897
3,984,765Darden Restaurants, Inc.
35,380
1,130,037International Game Technology
88,964
2,222,321Marriott International, Inc. "A"
83,964
2,203,215McDonald's Corp.
321,856
18,094,744Starbucks Corp.*
212,308
3,341,728Starwood Hotels & Resorts Worldwide, Inc.
55,512
2,224,366Wendy's International, Inc.
23,480
639,126Wyndham Worldwide Corp.
47,714
854,558Yum! Brands, Inc.
127,282
4,466,32539,161,185Household Durables 0.4%Black & Decker Corp.
16,552
951,906Centex Corp.
32,104
429,230D.R. Horton, Inc.
84,100
912,485Fortune Brands, Inc.
40,354
2,518,493Harman International Industries, Inc.
16,100
666,379KB HOME
25,172
426,162Leggett & Platt, Inc.
46,666
782,589Lennar Corp. "A"
42,100
519,514Newell Rubbermaid, Inc.
72,150
1,211,399Pulte Homes, Inc.
57,356
552,338Snap-on, Inc.
15,532
807,819The Stanley Works
19,653
881,044Whirlpool Corp.
19,377
1,196,14211,855,500Internet & Catalog Retail 0.3%Amazon.com, Inc.*
87,012
6,380,590Expedia, Inc.*
53,370
980,941IAC/InterActiveCorp.*
50,900
981,3528,342,883Leisure Equipment & Products 0.1%Eastman Kodak Co.
74,931
1,081,254Hasbro, Inc.
39,202
1,400,296Mattel, Inc.
95,814
1,640,3364,121,886Media 2.8%CBS Corp. "B"
180,054
3,509,252Clear Channel Communications, Inc.
147,763
5,201,258Comcast Corp. "A"
840,690
15,947,889E.W. Scripps Co. "A"
22,500
934,650Gannett Co., Inc.
61,169
1,325,532Interpublic Group of Companies, Inc.*
118,495
1,019,057McGraw-Hill Companies, Inc.
94,574
3,794,309Meredith Corp.
10,638
300,949New York Times Co. "A"
39,173
602,872News Corp. "A"
618,700
9,305,248Omnicom Group, Inc.
86,336
3,874,760The DIRECTV Group, Inc.*
188,700
4,889,217Time Warner, Inc.
1,017,112
15,053,258Viacom, Inc. "B"*
172,354
5,263,691Walt Disney Co.
536,964
16,753,277Washington Post Co. "B"
1,500
880,35088,655,569Multiline Retail 0.7%Big Lots, Inc.*
27,196
849,603Dillard's, Inc. "A"
15,068
174,337Family Dollar Stores, Inc.
37,072
739,216J.C. Penney Co., Inc.
58,275
2,114,800Kohl's Corp.*
83,538
3,344,861Macy's, Inc.
114,450
2,222,619Nordstrom, Inc.
48,432
1,467,490Sears Holdings Corp.*
18,838
1,387,607Target Corp.
217,691
10,120,45422,420,987Specialty Retail 1.5%Abercrombie & Fitch Co. "A"
22,600
1,416,568AutoNation, Inc.*
36,759
368,325AutoZone, Inc.*
12,208
1,477,290Bed Bath & Beyond, Inc.*
70,866
1,991,335Best Buy Co., Inc.
92,272
3,653,971GameStop Corp. "A"*
41,800
1,688,720Home Depot, Inc.
479,047
11,219,281Limited Brands, Inc.
83,311
1,403,790Lowe's Companies, Inc.
416,374
8,639,760Office Depot, Inc.*
72,859
797,077RadioShack Corp.
37,695
462,518Staples, Inc.
187,673
4,457,234The Gap, Inc.
124,958
2,083,050The Sherwin-Williams Co.
28,505
1,309,235Tiffany & Co.
35,716
1,455,427TJX Companies, Inc.
118,299
3,722,87046,146,451Textiles, Apparel & Luxury Goods 0.4%Coach, Inc.*
98,100
2,833,128Jones Apparel Group, Inc.
22,660
311,575Liz Claiborne, Inc.
27,706
392,040NIKE, Inc. "B"
106,916
6,373,263Polo Ralph Lauren Corp.
16,000
1,004,480VF Corp.
22,640
1,611,51512,526,001Consumer Staples 10.6%Beverages 2.5%Anheuser-Busch Companies, Inc.
204,680
12,714,722Brown-Forman Corp. "B"
21,578
1,630,649Coca-Cola Co.
557,435
28,975,471Coca-Cola Enterprises, Inc.
74,924
1,296,185Constellation Brands, Inc. "A"*
52,200
1,036,692Molson Coors Brewing Co. "B"
39,204
2,129,953Pepsi Bottling Group, Inc.
37,262
1,040,355PepsiCo, Inc.
450,150
28,625,03977,449,066Food & Staples Retailing 2.7%Costco Wholesale Corp.
122,033
8,559,394CVS Caremark Corp.
405,291
16,037,365Kroger Co.
196,563
5,674,774Safeway, Inc.
115,407
3,294,870SUPERVALU, Inc.
54,991
1,698,672Sysco Corp.
160,390
4,412,329Wal-Mart Stores, Inc.
647,854
36,409,395Walgreen Co.
266,478
8,663,200Whole Foods Market, Inc.
37,100
878,89985,628,898Food Products 1.5%Archer-Daniels-Midland Co.
183,753
6,201,664Campbell Soup Co.
53,409
1,787,065ConAgra Foods, Inc.
128,752
2,482,339Dean Foods Co.*
34,700
680,814General Mills, Inc.
97,150
5,903,805H.J. Heinz Co.
83,854
4,012,414Kellogg Co.
67,034
3,218,973Kraft Foods, Inc. "A"
438,884
12,486,250McCormick & Co., Inc.
35,600
1,269,496Sara Lee Corp.
190,439
2,332,878The Hershey Co.
44,460
1,457,399Tyson Foods, Inc. "A"
68,500
1,023,390Wm. Wrigley Jr. Co.
59,302
4,612,50947,468,996Household Products 2.2%Clorox Co.
36,332
1,896,530Colgate-Palmolive Co.
147,068
10,162,399Kimberly-Clark Corp.
112,307
6,713,712Procter & Gamble Co.
850,096
51,694,33870,466,979Personal Products 0.2%Avon Products, Inc.
113,770
4,097,995Estee Lauder Companies, Inc. "A"
30,500
1,416,7255,514,720Tobacco 1.5%Altria Group, Inc.
603,252
12,402,861Lorillard, Inc.*
48,554
3,357,995Philip Morris International, Inc.*
578,452
28,569,744Reynolds American, Inc.
44,990
2,099,684UST, Inc.
41,851
2,285,48348,715,767Energy 16.0%Energy Equipment & Services 3.6%Baker Hughes, Inc.
89,173
7,788,370BJ Services Co.
76,628
2,447,498Cameron International Corp.*
59,100
3,271,185ENSCO International, Inc.
38,700
3,124,638Halliburton Co.
251,978
13,372,472Nabors Industries Ltd.*
73,438
3,615,353National-Oilwell Varco, Inc.*
118,700
10,531,064Noble Corp.
70,548
4,582,798Rowan Companies, Inc.
29,039
1,357,573Schlumberger Ltd.
336,844
36,187,151Smith International, Inc.
52,700
4,381,478Transocean, Inc.*
89,799
13,684,470Weatherford International Ltd.*
182,200
9,035,298113,379,348Oil, Gas & Consumable Fuels 12.4%Anadarko Petroleum Corp.
125,968
9,427,445Apache Corp.
95,674
13,298,686Cabot Oil & Gas Corp.
27,100
1,835,483Chesapeake Energy Corp.
138,500
9,135,460Chevron Corp.
576,556
57,153,996ConocoPhillips
435,309
41,088,816CONSOL Energy, Inc.
49,100
5,517,367Devon Energy Corp.
126,604
15,212,737El Paso Corp.
183,098
3,980,551EOG Resources, Inc.
66,800
8,764,160ExxonMobil Corp.
1,477,568
130,218,068Hess Corp.
80,065
10,103,402Marathon Oil Corp.
200,688
10,409,687Massey Energy Co.
20,700
1,940,625Murphy Oil Corp.
49,600
4,863,280Noble Energy, Inc.
44,700
4,495,032Occidental Petroleum Corp.
233,262
20,960,923Peabody Energy Corp.
77,200
6,797,460Range Resources Corp.
39,342
2,578,475Southwestern Energy Co.*
94,900
4,518,189Spectra Energy Corp.
166,198
4,776,531Sunoco, Inc.
30,872
1,256,182Tesoro Corp.
36,400
719,628Valero Energy Corp.
153,100
6,304,658Williams Companies, Inc.
156,823
6,321,535XTO Energy, Inc.
137,750
9,437,252391,115,628Financials 14.0%Capital Markets 2.8%American Capital Strategies Ltd.
47,500
1,129,075Ameriprise Financial, Inc.
61,808
2,513,731Bank of New York Mellon Corp.
325,092
12,298,230Charles Schwab Corp.
267,833
5,501,290E*TRADE Financial Corp.*
109,700
344,458Federated Investors, Inc. "B"
22,900
788,218Franklin Resources, Inc.
42,071
3,855,807Janus Capital Group, Inc.
41,479
1,097,949Legg Mason, Inc.
34,900
1,520,593Lehman Brothers Holdings, Inc.
200,144
3,964,853Merrill Lynch & Co., Inc.
279,504
8,863,072Morgan Stanley
314,164
11,331,896Northern Trust Corp.
54,505
3,737,408State Street Corp.
117,434
7,514,602T. Rowe Price Group, Inc.
69,652
3,933,248The Goldman Sachs Group, Inc.
111,269
19,460,94887,855,378Commercial Banks 2.1%BB&T Corp.
145,118
3,304,337Comerica, Inc.
40,757
1,044,602Fifth Third Bancorp.
140,791
1,433,252First Horizon National Corp.
33,591
249,581Huntington Bancshares, Inc.
95,596
551,589KeyCorp.
134,283
1,474,427M&T Bank Corp.
19,700
1,389,638Marshall & Ilsley Corp.
62,253
954,339National City Corp.
176,923
843,923PNC Financial Services Group, Inc.
89,861
5,131,063Regions Financial Corp.
185,019
2,018,557SunTrust Banks, Inc.
91,192
3,302,974U.S. Bancorp.
493,515
13,764,133Wachovia Corp.
605,651
9,405,760Wells Fargo & Co.
937,056
22,255,080Zions Bancorp.
24,856
782,71667,905,971Consumer Finance 0.6%American Express Co.
320,643
12,078,622Capital One Financial Corp.
102,743
3,905,261Discover Financial Services
124,732
1,642,720SLM Corp.*
135,565
2,623,18320,249,786Diversified Financial Services 3.3%Bank of America Corp.
1,255,595
29,971,053CIT Group, Inc.
78,300
533,223Citigroup, Inc.
1,526,260
25,580,118CME Group, Inc.
15,400
5,901,126IntercontinentalExchange, Inc.*
18,100
2,063,400JPMorgan Chase & Co.
971,443
33,330,209Leucadia National Corp.
43,300
2,032,502Moody's Corp.
56,700
1,952,748NYSE Euronext
70,200
3,556,332104,920,711Insurance 3.5%ACE Ltd.
86,528
4,766,828Aflac, Inc.
138,544
8,700,563Allstate Corp.
155,870
7,106,113American International Group, Inc.
747,348
19,774,828Aon Corp.
77,787
3,573,535Assurant, Inc.
25,700
1,695,172Chubb Corp.
106,658
5,227,309Cincinnati Financial Corp.
45,234
1,148,944Genworth Financial, Inc. "A"
113,100
2,014,311Hartford Financial Services Group, Inc.
83,946
5,420,393Lincoln National Corp.
71,174
3,225,606Loews Corp.
100,023
4,691,079Marsh & McLennan Companies, Inc.
142,432
3,781,570MBIA, Inc.
53,046
232,872MetLife, Inc.
204,211
10,776,214Principal Financial Group, Inc.
69,419
2,913,515Progressive Corp.
190,388
3,564,063Prudential Financial, Inc.
128,616
7,683,520Safeco Corp.
24,889
1,671,545The Travelers Companies, Inc.
178,975
7,767,515Torchmark Corp.
25,010
1,466,836Unum Group
85,794
1,754,487XL Capital Ltd. "A"
47,732
981,370109,938,188Real Estate Investment Trusts 1.2%Apartment Investment & Management Co. "A" (REIT)
28,082
956,473AvalonBay Communities, Inc. (REIT)
20,000
1,783,200Boston Properties, Inc. (REIT)
30,500
2,751,710Developers Diversified Realty Corp. (REIT)
34,500
1,197,495Equity Residential (REIT)
72,360
2,769,217General Growth Properties, Inc. (REIT)
80,000
2,802,400HCP, Inc. (REIT)
58,200
1,851,342Host Hotels & Resorts, Inc. (REIT)
136,500
1,863,225Kimco Realty Corp. (REIT)
60,600
2,091,912Plum Creek Timber Co., Inc. (REIT)
45,624
1,948,601ProLogis (REIT)
79,500
4,320,825Public Storage (REIT)
34,530
2,789,679Simon Property Group, Inc. (REIT)
67,234
6,043,664Vornado Realty Trust (REIT)
38,800
3,414,40036,584,143Real Estate Management & Development 0.0%CB Richard Ellis Group, Inc. "A"*
50,200
963,840Thrifts & Mortgage Finance 0.5%Countrywide Financial Corp.
153,744
653,412Fannie Mae
302,928
5,910,125Freddie Mac
177,731
2,914,788Hudson City Bancorp., Inc.
133,400
2,225,112MGIC Investment Corp.
22,163
135,416Sovereign Bancorp., Inc.
132,791
977,342Washington Mutual, Inc.
294,359
1,451,19014,267,385Health Care 11.8%Biotechnology 1.4%Amgen, Inc.*
308,624
14,554,708Biogen Idec, Inc.*
79,071
4,419,278Celgene Corp.*
120,700
7,709,109Genzyme Corp.*
70,340
5,065,887Gilead Sciences, Inc.*
263,220
13,937,49945,686,481Health Care Equipment & Supplies 2.1%Baxter International, Inc.
181,698
11,617,770Becton, Dickinson & Co.
68,192
5,544,010Boston Scientific Corp.*
358,506
4,406,039C.R. Bard, Inc.
26,994
2,374,122Covidien Ltd.
132,157
6,328,999Hospira, Inc.*
41,622
1,669,458Intuitive Surgical, Inc.*
11,500
3,098,100Medtronic, Inc.
319,199
16,518,548St. Jude Medical, Inc.*
89,626
3,663,911Stryker Corp.
61,948
3,895,290Varian Medical Systems, Inc.*
33,000
1,711,050Zimmer Holdings, Inc.*
63,308
4,308,10965,135,406Health Care Providers & Services 1.8%Aetna, Inc.
131,396
5,325,480AmerisourceBergen Corp.
43,848
1,753,482Cardinal Health, Inc.
95,268
4,913,923CIGNA Corp.
74,375
2,632,131Coventry Health Care, Inc.*
40,958
1,245,942Express Scripts, Inc.*
66,600
4,177,152Humana, Inc.*
46,751
1,859,287Laboratory Corp. of America Holdings*
30,800
2,144,604McKesson Corp.
77,815
4,350,637Medco Health Solutions, Inc.*
148,576
7,012,787Patterson Companies, Inc.*
36,600
1,075,674Quest Diagnostics, Inc.
41,802
2,026,143Tenet Healthcare Corp.*
123,848
688,595UnitedHealth Group, Inc.
342,724
8,996,505WellPoint, Inc.*
151,516
7,221,25355,423,595Health Care Technology 0.0%IMS Health, Inc.
50,906
1,186,110Life Sciences Tools & Services 0.4%Applera Corp.  Applied Biosystems Group
48,235
1,614,908Millipore Corp.*
13,981
948,751PerkinElmer, Inc.
31,663
881,815Thermo Fisher Scientific, Inc.*
120,228
6,700,306Waters Corp.*
26,105
1,683,77211,829,552Pharmaceuticals 6.1%Abbott Laboratories
437,022
23,149,055Allergan, Inc.
80,878
4,209,700Barr Pharmaceuticals, Inc.*
28,800
1,298,304Bristol-Myers Squibb Co.
562,936
11,557,076Eli Lilly & Co.
267,747
12,359,202Forest Laboratories, Inc.*
83,081
2,886,234Johnson & Johnson
792,901
51,015,250King Pharmaceuticals, Inc.*
64,975
680,288Merck & Co., Inc.
607,306
22,889,363Mylan, Inc.
70,000
844,900Pfizer, Inc.
1,894,693
33,100,287Schering-Plough Corp.
458,552
9,028,889Watson Pharmaceuticals, Inc.*
27,407
744,648Wyeth
368,909
17,692,876191,456,072Industrials 10.9%Aerospace & Defense 2.6%Boeing Co.
212,720
13,979,958General Dynamics Corp.
109,960
9,258,632Goodrich Corp.
32,038
1,520,524Honeywell International, Inc.
213,468
10,733,171L-3 Communications Holdings, Inc.
33,100
3,007,797Lockheed Martin Corp.
98,426
9,710,709Northrop Grumman Corp.
88,850
5,944,065Precision Castparts Corp.
41,100
3,960,807Raytheon Co.
112,723
6,344,051Rockwell Collins, Inc.
42,344
2,030,818United Technologies Corp.
276,840
17,081,02883,571,560Air Freight & Logistics 0.9%C.H. Robinson Worldwide, Inc.
45,400
2,489,736Expeditors International of Washington, Inc.
56,000
2,408,000FedEx Corp.
84,201
6,634,197United Parcel Service, Inc. "B"
292,670
17,990,42529,522,358Airlines 0.1%Southwest Airlines Co.
196,491
2,562,243Building Products 0.0%Masco Corp.
96,805
1,522,743Commercial Services & Supplies 0.5%Allied Waste Industries, Inc.*
76,846
969,797Avery Dennison Corp.
25,231
1,108,398Cintas Corp.
34,366
911,043Equifax, Inc.
34,409
1,156,831Monster Worldwide, Inc.*
33,189
684,025Pitney Bowes, Inc.
57,485
1,960,238R.R. Donnelley & Sons Co.
58,621
1,740,457Robert Half International, Inc.
43,775
1,049,287Waste Management, Inc.
146,540
5,526,02315,106,099Construction & Engineering 0.2%Fluor Corp.
26,204
4,876,040Jacobs Engineering Group, Inc.*
34,700
2,800,2907,676,330Electrical Equipment 0.5%Cooper Industries Ltd. "A"
47,602
1,880,279Emerson Electric Co.
217,440
10,752,408Rockwell Automation, Inc.
39,456
1,725,41114,358,098Industrial Conglomerates 3.1%3M Co.
196,966
13,706,864General Electric Co.
2,789,665
74,456,159Textron, Inc.
65,654
3,146,796Tyco International Ltd.
142,057
5,687,96296,997,781Machinery 1.9%Caterpillar, Inc.
173,568
12,812,790Cummins, Inc.
53,892
3,531,004Danaher Corp.
70,222
5,428,161Deere & Co.
119,992
8,655,023Dover Corp.
52,559
2,542,279Eaton Corp.
45,554
3,870,723Illinois Tool Works, Inc.
109,242
5,190,087Ingersoll-Rand Co., Ltd. "A"
83,672
3,131,843ITT Corp.
47,592
3,014,001Manitowoc Co., Inc.
33,500
1,089,755PACCAR, Inc.
105,815
4,426,241Pall Corp.
32,710
1,297,933Parker Hannifin Corp.
44,452
3,170,317Terex Corp.*
27,100
1,392,12759,552,284Road & Rail 1.1%Burlington Northern Santa Fe Corp.
78,486
7,839,967CSX Corp.
115,952
7,282,945Norfolk Southern Corp.
101,544
6,363,762Ryder System, Inc.
15,290
1,053,175Union Pacific Corp.
149,930
11,319,71533,859,564Trading Companies & Distributors 0.0%W.W. Grainger, Inc.
17,962
1,469,291Information Technology 16.1%Communications Equipment 2.5%Ciena Corp.*
22,698
525,913Cisco Systems, Inc.*
1,644,864
38,259,537Corning, Inc.
447,890
10,323,864JDS Uniphase Corp.*
58,939
669,547Juniper Networks, Inc.*
136,900
3,036,442Motorola, Inc.
649,796
4,769,503QUALCOMM, Inc.
457,154
20,283,923Tellabs, Inc.*
117,630
546,97978,415,708Computers & Peripherals 4.6%Apple, Inc.*
245,278
41,069,348Dell, Inc.*
561,047
12,275,708EMC Corp.*
594,262
8,729,709Hewlett-Packard Co.
686,736
30,360,599International Business Machines Corp.
386,920
45,861,628Lexmark International, Inc. "A"*
25,157
840,998NetApp, Inc.*
93,509
2,025,405QLogic Corp.*
36,500
532,535SanDisk Corp.*
59,500
1,112,650Sun Microsystems, Inc.*
217,791
2,369,566Teradata Corp.*
47,698
1,103,732146,281,878Electronic Equipment & Instruments 0.3%Agilent Technologies, Inc.*
101,041
3,590,997Jabil Circuit, Inc.
48,675
798,757Molex, Inc.
37,786
922,356Tyco Electronics Ltd.
130,657
4,680,1349,992,244Internet Software & Services 1.7%Akamai Technologies, Inc.*
43,500
1,513,365eBay, Inc.*
303,132
8,284,598Google, Inc. "A"*
65,000
34,217,300VeriSign, Inc.*
57,700
2,181,060Yahoo!, Inc.*
376,722
7,783,07653,979,399IT Services 0.9%Affiliated Computer Services, Inc. "A"*
26,600
1,422,834Automatic Data Processing, Inc.
149,637
6,269,790Cognizant Technology Solutions Corp. "A"*
77,000
2,503,270Computer Sciences Corp.*
45,432
2,128,035Convergys Corp.*
35,440
526,638Electronic Data Systems Corp.
148,619
3,661,972Fidelity National Information Services, Inc.
43,200
1,594,512Fiserv, Inc.*
43,850
1,989,475Paychex, Inc.
90,967
2,845,448Total System Services, Inc.
45,466
1,010,255Unisys Corp.*
94,084
371,632Western Union Co.
203,088
5,020,33529,344,196Office Electronics 0.1%Xerox Corp.
246,056
3,336,519Semiconductors & Semiconductor Equipment 2.5%Advanced Micro Devices, Inc.*
149,897
873,900Altera Corp.
82,243
1,702,430Analog Devices, Inc.
78,668
2,499,282Applied Materials, Inc.
385,335
7,356,045Broadcom Corp. "A"*
122,870
3,353,122Intel Corp.
1,594,982
34,260,213KLA-Tencor Corp.
47,585
1,937,185Linear Technology Corp.
58,306
1,899,026LSI Corp.*
191,155
1,173,692MEMC Electronic Materials, Inc.*
60,800
3,741,632Microchip Technology, Inc.
57,100
1,743,834Micron Technology, Inc.*
188,649
1,131,894National Semiconductor Corp.
63,166
1,297,430Novellus Systems, Inc.*
30,482
645,914NVIDIA Corp.*
144,947
2,713,408Teradyne, Inc.*
45,658
505,434Texas Instruments, Inc.
378,948
10,671,176Xilinx, Inc.
76,613
1,934,47879,440,095Software 3.5%Adobe Systems, Inc.*
146,104
5,755,037Autodesk, Inc.*
60,448
2,043,747BMC Software, Inc.*
52,569
1,892,484CA, Inc.
101,515
2,343,981Citrix Systems, Inc.*
47,514
1,397,387Compuware Corp.*
80,921
771,986Electronic Arts, Inc.*
82,906
3,683,514Intuit, Inc.*
88,566
2,441,765Microsoft Corp.
2,244,095
61,735,053Novell, Inc.*
92,382
544,130Oracle Corp.*
1,112,729
23,367,309Symantec Corp.*
236,406
4,574,456110,550,849Materials 3.8%Chemicals 2.1%Air Products & Chemicals, Inc.
56,790
5,614,259Ashland, Inc.
14,604
703,913Dow Chemical Co.
270,091
9,428,877E.I. du Pont de Nemours & Co.
258,352
11,080,717Eastman Chemical Co.
22,386
1,541,500Ecolab, Inc.
45,542
1,957,851Hercules, Inc.
31,330
530,417International Flavors & Fragrances, Inc.
21,116
824,791Monsanto Co.
154,684
19,558,245PPG Industries, Inc.
43,162
2,476,204Praxair, Inc.
85,328
8,041,311Rohm & Haas Co.
33,089
1,536,653Sigma-Aldrich Corp.
34,268
1,845,67465,140,412Construction Materials 0.1%Vulcan Materials Co.
26,731
1,597,979Containers & Packaging 0.1%Ball Corp.
27,424
1,309,222Bemis Co., Inc.
27,430
614,980Pactiv Corp.*
34,849
739,844Sealed Air Corp.
43,072
818,7993,482,845Metals & Mining 1.3%Alcoa, Inc.
233,551
8,319,087Allegheny Technologies, Inc.
25,679
1,522,251Freeport-McMoRan Copper & Gold, Inc.
108,499
12,714,998Newmont Mining Corp.
127,100
6,629,536Nucor Corp.
86,836
6,484,044Titanium Metals Corp.
23,400
327,366United States Steel Corp.
33,892
6,262,56442,259,846Paper & Forest Products 0.2%International Paper Co.
119,104
2,775,123MeadWestvaco Corp.
48,244
1,150,137Weyerhaeuser Co.
58,529
2,993,1736,918,433Telecommunication Services 3.3%Diversified Telecommunication Services 2.9%AT&T, Inc.
1,654,230
55,731,009CenturyTel, Inc.
29,755
1,058,980Citizens Communications Co.
86,005
975,297Embarq Corp.
41,181
1,946,626Qwest Communications International, Inc.
421,981
1,658,385Verizon Communications, Inc.
796,312
28,189,445Windstream Corp.
125,474
1,548,34991,108,091Wireless Telecommunication Services 0.4%American Tower Corp. "A"*
107,500
4,541,875Sprint Nextel Corp.
793,828
7,541,36612,083,241Utilities 3.9%Electric Utilities 2.3%Allegheny Energy, Inc.
43,418
2,175,676American Electric Power Co., Inc.
104,915
4,220,730Duke Energy Corp.
353,396
6,142,022Edison International
85,090
4,371,924Entergy Corp.
56,609
6,820,252Exelon Corp.
188,738
16,978,871FirstEnergy Corp.
90,895
7,483,385FPL Group, Inc.
118,794
7,790,511Pepco Holdings, Inc.
51,700
1,326,105Pinnacle West Capital Corp.
26,196
806,051PPL Corp.
100,048
5,229,509Progress Energy, Inc.
67,650
2,829,800Southern Co.
222,088
7,755,31373,930,149Gas Utilities 0.1%Nicor, Inc.
12,337
525,433Questar Corp.
45,100
3,203,9043,729,337Independent Power Producers & Energy Traders 0.3%AES Corp.*
175,750
3,376,157Constellation Energy Group, Inc.
53,687
4,407,703Dynegy, Inc. "A"*
113,261
968,3828,752,242Multi-Utilities 1.2%Ameren Corp.
56,319
2,378,351CenterPoint Energy, Inc.
83,568
1,341,266CMS Energy Corp.
59,049
879,830Consolidated Edison, Inc.
66,816
2,611,838Dominion Resources, Inc.
152,080
7,222,279DTE Energy Co.
44,603
1,892,951Integrys Energy Group, Inc.
20,100
1,021,683NiSource, Inc.
72,066
1,291,423PG&E Corp.
92,347
3,665,252Public Service Enterprise Group, Inc.
150,546
6,914,578Sempra Energy
79,890
4,509,791TECO Energy, Inc.
55,888
1,201,033Xcel Energy, Inc.
108,737
2,182,35237,112,627Total Common Stocks (Cost $2,478,885,713)
3,108,116,214 Principal
Amount ($)
Value ($)Government & Agency Obligation 0.1%US Treasury ObligationUS Treasury Bill, 2.06%**, 12/4/2008 (a) (Cost $3,280,453)
3,310,000
3,280,137 Shares
Value ($)Cash Equivalents 1.4%Cash Management QP Trust, 2.49% (b) (Cost $43,180,580)
43,180,580
43,180,580 % of Net
Assets
Value ($)Total Investment Portfolio(Cost $2,525,346,746)+
99.9
3,154,576,931Other Assets and Liabilities, Net
0.1
4,236,828Net Assets
100.0
3,158,813,759 * Non-income producing security  ** Annualized yield at time of purchase; not a coupon rate.  +  The cost for federal income tax purposes was $2,711,593,798. At June 30, 2008, net
unrealized appreciation for all securities based on tax cost was $442,983,133. This
consisted of aggregate gross unrealized appreciation for all securities in which there was
an excess of value over tax cost of $1,018,078,953 and aggregate gross unrealized
depreciation for all securities in which there was an excess of tax cost over value of
$575,095,820.  (a) At June 30, 2008, this security has been pledged, in whole or in part, to cover initial
margin requirements for open futures contracts.  (b) Affiliated fund managed by Deutsche Investment Management Americas Inc. The rate
shown is the annualized seven-day yield at period end.  REIT: Real Estate Investment Trust At June 30, 2008, open futures contracts purchased were as follows: Futures
Expiration
Date
Contracts
Aggregate
Face
Value ($)
Value ($)
Unrealized
Depreciation ($)S&P 500 Index
9/18/2008
151
51,165,917
48,361,525
(2,804,392) Fair Value Measurements The following is a summary of the inputs used as of June 30, 2008 in valuing the Fund's
assets carried at fair value. The inputs or methodology used for valuing securities may not be
an indication of the risk associated with investing in those securities. For information on the
Fund's policy regarding the valuation of investments and of the valuation inputs, and their
aggregate levels used in the table below, please refer to the Security Valuation section in the
accompanying Notes to Financial Statements. Valuation Inputs
Investments in
Securities at
Value
Net Unrealized
Depreciation on
Other Financial
Instruments++Level 1  Quoted Prices
$       3,151,296,794
$       (2,804,392)Level 2  Other Significant Observable Inputs
3,280,137
Level 3  Significant Unobservable Inputs

Total
$    3,154,576,931
$    (2,804,392) + + Other financial instruments are derivative instruments not reflected in the Portfolio of
Investments, such as future contracts, which are valued at the unrealized
appreciation/depreciation on the instrument.  The accompanying notes are an integral part of the financial statements. Financial Statements Statement of Assets and Liabilitiesas of June 30, 2008 (Unaudited)AssetsInvestments:Investments in securities, at value (cost $2,482,166,166)
$       3,111,396,351Investment in Cash Management QP Trust (cost $43,180,580)
43,180,580Total investments in securities, at value (cost $2,525,346,746)
3,154,576,931Cash
10,062Dividends receivable
4,123,629Interest receivable
92,843Receivable for daily variation margin on open futures contracts
36,553Due from Advisor
17,848Other assets
100,014Total assets
3,158,957,880LiabilitiesOther accrued expenses and payables
144,121Total liabilities
144,121Net assets
$    3,158,813,759 The accompanying notes are an integral part of the financial statements. Statement of Operationsfor the six months ended June 30, 2008 (Unaudited)Investment IncomeIncome:Dividends
$       33,685,021Interest  Cash Management QP Trust
662,672Interest
43,498Total Income
34,391,191Expenses:Investment management fee
814,500Administration fee
488,701Professional fees
44,920Custodian fees
47,044Trustees' fees and expenses
76,662Reports to shareholders
8,346Other
52,112Total expenses before expense reductions
1,532,285Expense reductions
(717,529)Total expenses after expense reductions
814,756Net investment income (loss)
33,576,435Realized and Unrealized Gain (Loss)Net realized gain (loss) from:Investments
(2,931,850)Futures
(5,370,880)(8,302,730)Change in net unrealized appreciation (depreciation) during the period on:Investments
(442,376,066)Futures
(2,619,802)(444,995,868)Net gain (loss)
(453,298,598)Net increase (decrease) in net assets resulting from operations
$    (419,722,163) The accompanying notes are an integral part of the financial statements. Statement of Changes in Net AssetsIncrease (Decrease) in Net Assets
Six Months
Ended June 30,
2008
(Unaudited)
Year Ended
December 31,
2007Operations:Net investment income (loss)
$       33,576,435
$       69,228,757Net realized gain (loss)
(8,302,730)
71,989,267Change in net unrealized appreciation (depreciation)
(444,995,868)
57,451,772Net increase (decrease) in net assets resulting from
operations
(419,722,163)
198,669,796Capital transactions in shares of beneficial interest:Proceeds from capital invested
442,674,091
649,751,320Value of capital withdrawn
(272,804,506)
(988,879,233)Net increase (decrease) in net assets from capital
transactions in shares of beneficial interest
169,869,585
(339,127,913)Increase (decrease) in net assets
(249,852,578)
(140,458,117)Net assets at beginning of period
3,408,666,337
3,549,124,454Net assets at end of period
$    3,158,813,759
$    3,408,666,337 The accompanying notes are an integral part of the financial statements. Financial Highlights Years Ended December 31,
2008a
2007
2006
2005
2004
2003Ratios to Average Net Assets and Supplemental DataNet assets, end of period
($ millions)
3,159
3,409
3,549
3,307
3,272
3,260Ratio of expenses before expense
reductions (%)
.09*
.09
.08
.06
.06
.05Ratio of expenses after expense
reductions (%)
.05*
.05
.05
.05
.05
.05Ratio of net investment income
(loss) (%)
2.06*
1.91
1.90
1.82
1.97
1.74Portfolio turnover rate (%)
1**
5
4
9
7
8bTotal investment return (%)c,d
(12.00)**
5.54
15.72
4.90
10.79
28.50aFor the six months ended June 30, 2008 (Unaudited).bExcludes portfolio securities delivered as a result of processing redemption in-kind
transactions.cTotal investment return would have been lower had certain expenses not been reduced.dTotal investment return for the Portfolio was derived from the performance of the
Institutional Class of DWS Equity 500 Index Fund.*Annualized**Not annualized Notes to Financial Statements(Unaudited) A. Significant Accounting Policies DWS Equity 500 Index Portfolio (the "Portfolio") is registered under the
Investment Company Act of 1940, as amended (the "1940 Act"), as a
diversified open-end management investment company organized
as a New York business trust. The Portfolio's financial statements are prepared in accordance with
accounting principles generally accepted in the United States of America
which require the use of management estimates. Actual results could
differ from those estimates. The policies described below are followed
consistently by the Portfolio in the preparation of its financial statements. Security Valuation. Investments are stated at value determined as of the
close of regular trading on the New York Stock Exchange on each day the
exchange is open for trading. Equity securities are valued at the most
recent sale price or official closing price reported on the exchange (US or
foreign) or over-the-counter market on which the security is traded most
extensively. Securities for which no sales are reported are valued at the
calculated mean between the most recent bid and asked quotations on
the relevant market or, if a mean cannot be determined, at the most
recent bid quotation. Money market instruments purchased with an original or remaining
maturity of sixty days or less, maturing at par, are valued at amortized
cost. Investments in open-end investment companies and Cash
Management QP Trust are valued at their net asset value each business
day. Securities and other assets for which market quotations are not readily
available or for which the above valuation procedures are deemed not to
reflect fair value are valued in a manner that is intended to reflect their fair
value as determined in accordance with procedures approved by the
Trustees. The Portfolio adopted Financial Accounting Standards Board Statement of
Financial Accounting Standards No. 157, Fair Value Measurements ("FAS
157"), which governs the application of generally accepted accounting
principles that require fair value measurements of the Portfolio's assets
and liabilities. Fair value is an estimate of the price the Portfolio would
receive upon selling a security in a timely transaction to an independent
buyer in the principal or most advantageous market of the security. FAS
157 established a three-tier hierarchy to maximize the use of observable
market data and minimize the use of unobservable inputs and to establish
classification of fair value measurements for disclosure purposes. Inputs
refer broadly to the assumptions that market participants would use in
pricing the asset or liability, including assumptions about risk, for example,
the risk inherent in a particular valuation technique used to measure fair
value including such a pricing model and/or the risk inherent in the inputs
to the valuation technique. Inputs may be observable or unobservable.
Observable inputs are inputs that reflect the assumptions market
participants would use in pricing the asset or liability developed based on
market data obtained from sources independent of the reporting entity.
Unobservable inputs are inputs that reflect the reporting entity's own
assumptions about the assumptions market participants would use in
pricing the asset or liability developed based on the best information
available in the circumstances. Various inputs are used in determining the value of the Portfolio's
investments. These inputs are summarized in the three broad levels as
follows: •    Level 1  quoted prices in active markets for identical securities •    Level 2  other significant observable inputs (including quoted prices
for similar securities, interest rates, prepayment speeds, credit risk,
etc.) •    Level 3  significant unobservable inputs (including the Portfolio's own
assumptions in determining the fair value of investments) For Level 1 inputs, the Portfolio uses unadjusted quoted prices in active
markets for assets or liabilities with sufficient frequency and volume to
provide pricing information as the most reliable evidence of fair value. The
Portfolio's Level 2 valuation techniques include inputs other than quoted
prices within Level 1 that are observable for an asset or liability, either
directly or indirectly. Level 2 observable inputs may include quoted prices
for similar assets and liabilities in active markets or quoted prices for
identical or similar assets or liabilities in markets that are not active in
which there are few transactions, the prices are not current, or price
quotations vary substantially over time or among market participants.
Inputs that are observable for the asset or liability in Level 2 include such
factors as interest rates, yield curves, prepayment speeds, credit risk, and
default rates for similar liabilities. For Level 3 valuation techniques, the
Portfolio uses unobservable inputs that reflect assumptions market
participants would be expected to use in pricing the asset or liability.
Unobservable inputs are used to measure fair value to the extent that
observable inputs are not available and are developed based on the best
information available under the circumstances. In developing
unobservable inputs, market participant assumptions are used if they are
reasonably available without undue cost and effort. The Portfolio may record changes to valuations based on the amount that
might reasonably be expected to receive for a security upon its current
sale consistent with the fair value measurement objective. Each
determination is based on a consideration of all relevant factors, which are
likely to vary from one pricing context to another. Examples of such
factors may include, but are not limited to the type of the security, the
existence of any contractual restrictions on the security's disposition, the
price and extent of public trading in similar securities of the issue or of
comparable companies, quotations or evaluated prices from
broker-dealers and/or pricing services, information obtained from the
issuer, analysts, and/or the appropriate stock exchange (for
exchange-traded securities), an analysis of the company's financial
statements, an evaluation of the forces that influence the issuer and the
market(s) in which the security is purchased and sold, and with respect to
debt securities, the maturity, coupon, creditworthiness, currency
denomination, and the movement of the market in which the security is
normally traded. Because of the inherent uncertainties of valuation, the
values reflected in the financial statements may materially differ from the
value determined upon sale of those investments. New Accounting Pronouncement. In March 2008, FASB issued
Statement of Financial Accounting Standards No. 161 ("FAS 161")
Disclosures about Derivative Instruments and Hedging Activities, an
amendment of FASB Statement No. 133. FAS 161 requires enhanced
disclosure about an entity's derivative and hedging activities. FAS 161 is
effective for fiscal years beginning after November 15, 2008. Management
is currently evaluating the impact the adoption of FAS 161 will have on the
Portfolio's financial statement disclosures. Foreign Currency Transactions. The books and records of the Fund are
maintained in US dollars. Investment securities and other assets and
liabilities denominated in a foreign currency are translated into US dollars
at the prevailing exchange rates at period end. Purchases and sales of
investment securities, income and expenses are translated into US dollars
at the prevailing exchange rates on the respective dates of the
transactions. Net realized and unrealized gains and losses on foreign currency
transactions represent net gains and losses between trade and
settlement dates on securities transactions, the disposition of forward
foreign currency exchange contracts and foreign currencies, and the
difference between the amount of net investment income accrued and
the US dollar amount actually received. That portion of both realized and
unrealized gains and losses on investments that results from fluctuations
in foreign currency exchange rates is not separately disclosed but is
included with net realized and unrealized gain/appreciation and
loss/depreciation on investments. Futures Contracts. A futures contract is an agreement between a buyer or
seller and an established futures exchange or its clearinghouse in which
the buyer or seller agrees to take or make a delivery of a specific amount
of a financial instrument at a specified price on a specific date (settlement
date). The Portfolio enters into future contracts to keep cash on hand to
meet shareholder redemptions or other needs while maintaining exposure
to the stock market. Upon entering into a futures contract, the Portfolio is required to deposit
with a financial intermediary an amount ("initial margin") equal to a certain
percentage of the face value indicated in the futures contract. Subsequent
payments ("variation margin") are made or received by the Portfolio
dependent upon the daily fluctuations in the value of the underlying
security and are recorded for financial reporting purposes as unrealized
gains or losses by the Portfolio. When entering into a closing transaction,
the Portfolio will realize a gain or loss equal to the difference between the
value of the futures contract to sell and the futures contract to buy.
Futures contracts are valued at the most recent settlement price. Certain risks may arise upon entering into futures contracts, including the
risk that an illiquid secondary market will limit the Portfolio's ability to
close out a futures contract prior to the settlement date and that a change
in the value of a futures contract may not correlate exactly with the
changes in the value of the securities hedged. Federal Income Taxes. The Portfolio is considered a partnership under the
Internal Revenue Code, as amended. Therefore, no federal income tax
provision is necessary. The Portfolio has reviewed the tax positions for the open tax years as of
December 31, 2007 and has determined that no provision for income tax
is required in the Portfolio's financial statements. The Portfolio's federal
tax returns for the prior three fiscal years remain subject to examination
by the Internal Revenue Service. Contingencies. In the normal course of business, the Portfolio may enter
into contracts with service providers that contain general indemnification
clauses. The Portfolio's maximum exposure under these arrangements is
unknown as this would involve future claims that may be made against
the Portfolio that have not yet been made. However, based on experience,
the Portfolio expects the risk of loss to be remote. Other. Investment transactions are accounted for on a trade date plus one
basis for daily net asset value calculations. However, for financial reporting
purposes, investment security transactions are reported on trade date.
Interest income is recorded on the accrual basis. Dividend income is
recorded on the ex-dividend date. Realized gains and losses from
investment transactions are recorded on an identified cost basis. The Portfolio makes a daily allocation of its net investment income and
realized and unrealized gains and losses from securities, futures and
foreign currency transactions to its investors in proportion to their
investment in the Portfolio. B. Purchases and Sales of Securities During the six months ended June 30, 2008, purchases and sales of
investment securities (excluding short-term investments) aggregated
$216,874,707 and $43,865,605, respectively. C. Related Parties Deutsche Investment Management Americas Inc. ("DIMA" or the
"Advisor"), an indirect, wholly owned subsidiary of Deutsche Bank AG, is
the Advisor for the Portfolio. Management Agreement. Under the Investment Management
Agreement, the Advisor directs the investments of the Portfolio in
accordance with its investment objectives, policies and restrictions. The
Advisor determines the securities, instruments and other contracts
relating to investments to be purchased, sold or entered into by the
Portfolio or delegates such responsibility to the Portfolio's sub-advisor. The
investment management fee payable under the Investment Management
Agreement is equal to an annual rate of 0.05% of the Portfolio's average
daily net assets, computed and accrued daily and payable monthly.
Northern Trust Investments, N.A. ("NTI") serves as sub-advisor to the
Portfolio and is paid by the Advisor for its services. NTI is responsible for
the day to day management of the Portfolio. For the period from January 1, 2008 through September 30, 2008, DIMA
has contractually agreed to waive all or a portion of its investment
management fee and reimburse or pay certain operating expenses of the
Portfolio to the extent necessary to maintain the annual operating
expenses of the Portfolio at 0.05% of average daily net assets (excluding
certain expenses such as extraordinary expenses, taxes, brokerage and
interest). Accordingly, for the six months ended June 30, 2008, the Advisor waived
a portion of its investment management fee pursuant to the Investment
Management Agreement of $691,970 and charged $122,530, which was
equivalent to an annualized effective rate of 0.01% of the Portfolio's
average daily net assets. Administration Fee.Pursuant to an Administrative Services Agreement,
DIMA provides most administrative services to the Portfolio. For all
services provided under the Administrative Services Agreement, the
Portfolio pays the Advisor an annual fee ("Administration Fee") of 0.03%
of the Portfolio's average daily net assets, computed and accrued daily and
payable monthly. Accordingly, for the six months ended June 30, 2008,
DIMA received an Administration Fee of $488,701, of which $81,708 is
unpaid. Trustees' Fees and Expenses. The Portfolio paid each Trustee not affiliated
with the Advisor retainer fees plus specified amounts for various
committee services and for the Board Chairperson and Vice Chairperson. In connection with the board consolidation on April 1, 2008, of the two
DWS Funds Boards of Trustees, certain Independent Board Members
retired prior to their normal retirement date, and received a one-time
retirement benefit. DIMA has agreed to reimburse the Funds for the cost
of this benefit. During the period ended June 30, 2008, the Portfolio paid
its allocated portion of the retirement benefit of $16,748 to the
non-continuing Independent Board Members, and the Portfolio was
reimbursed by DIMA for this payment. Cash Management QP Trust. Pursuant to an Exemptive Order issued by
the SEC, the Portfolio may invest in the Cash Management QP Trust (the
"QP Trust") and other affiliated funds managed by the Advisor. The QP
Trust seeks to provide as high a level of current income as is consistent
with the preservation of capital and the maintenance of liquidity. The
QP Trust does not pay its Advisor a management fee for the affiliated
funds' investments in the QP Trust. D. Line of Credit The Portfolio and other affiliated funds (the "Participants") share in a
$490 million revolving credit facility provided by a syndication of banks.
The Portfolio may borrow for temporary or emergency purposes, including
the meeting of withdrawal requests that otherwise might require the
untimely disposition of securities. The Participants are charged an annual
commitment fee which is allocated based on net assets, among each of
the Participants. Interest is calculated at the Federal Funds Rate plus
0.35 percent. The Portfolio may borrow up to a maximum of 33 percent of
its net assets under the agreement. E. Fee Reductions The Portfolio has entered into an arrangement with its custodian and
transfer agent whereby credits realized as a result of uninvested cash
balances are used to reduce a portion of the Portfolio's custodian
expenses. During the six months ended June 30, 2008, the Portfolio's
custodian fees were reduced by $970 and $7,841, respectively, for
custody and transfer agent credits earned. Summary of Management Fee Evaluation
by Independent Fee Consultant October 26, 2007 Pursuant to an Order entered into by Deutsche Investment Management
Americas and affiliates (collectively, "DeAM") with the Attorney General
of New York, I, Thomas H. Mack, have been appointed the Independent
Fee Consultant for the DWS Scudder Funds. My duties include preparing
an annual written evaluation of the management fees DeAM charges the
Funds, considering among other factors the management fees charged by
other mutual fund companies for like services, management fees DeAM
charges other clients for like services, DeAM's costs of supplying services
under the management agreements and related profit margins, possible
economies of scale if a Fund grows larger, and the nature and quality of
DeAM's services, including fund performance. This report summarizes my
evaluation for 2007, including my qualifications, the evaluation process for
each of the DWS Scudder Funds, consideration of certain complex-level
factors, and my conclusions. Qualifications For more than 30 years I have served in various professional capacities
within the investment management business. I have held investment
analysis and advisory positions, including securities analyst, portfolio
strategist and director of investment policy with a large investment firm. I
have also performed business management functions, including business
development, financial management and marketing research and analysis. Since 1991, I have been an independent consultant within the asset
management industry. I have provided services to over 125 client
organizations, including investment managers, mutual fund boards,
product distributors and related organizations. Over the past several years
I have completed a number of assignments for mutual fund boards,
specifically including assisting boards with management contract renewal. I hold a Master of Business Administration degree, with highest honors,
from Harvard University; and Master of Science and Bachelor of Science
(highest honors) degrees from the University of California at Berkeley. I
am an independent director and audit committee financial expert for two
closed-end mutual funds, serve on the board of directors of a private
market research company, and have served in various leadership and
financial oversight capacities with non-profit organizations. Evaluation of Fees for each DWS Scudder Fund My work focused primarily on evaluating, fund-by-fund, the fees charged
to each of the 136 Fund portfolios in the DWS Scudder Fund family. For
each Fund, I considered each of the key factors mentioned above, as well
as any other relevant information. In doing so I worked closely with the
Funds' Independent Directors in their annual contract renewal process, as
well as in their approval of contracts for several new funds (documented
separately). In evaluating each Fund's fees, I reviewed comprehensive materials
provided by or on behalf of DeAM, including expense information
prepared by Lipper Analytical, comparative performance information,
profitability data, manager histories, and other materials. I also accessed
certain additional information from the Lipper, Strategic Insight, and
Morningstar databases and drew on my industry knowledge and
experience. To facilitate evaluating this considerable body of information, I prepared
for each Fund a document summarizing the key data elements in each
area as well as additional analytics discussed below. This made it possible
to consider each key data element in the context of the others. In the course of contract renewal, DeAM agreed to implement a number
of fee and expense adjustments requested by the Independent Directors
which will favorably impact future fees and expenses, and my evaluation
includes the effects of these changes. Fees and Expenses Compared with Other Funds The competitive fee and expense evaluation for each fund focused on two
primary comparisons: The Fund's contractual management fee (the advisory fee plus the
administration fee where applicable) compared with those of a group of
typically 12-15 funds in the same Lipper investment category (e.g.
Large Capitalization Growth) having similar distribution arrangements
and being of similar size. The Fund's total expenses compared with a broader universe of funds
from the same Lipper investment category and having similar
distribution arrangements. These two comparisons provide a view of not only the level of the fee
compared with funds of similar scale but also the total expense the Fund
bears for all the services it receives, in comparison with the investment
choices available in the Fund's investment category and distribution
channel. The principal figure-of-merit used in these comparisons was the
subject Fund's percentile ranking against peers. DeAM's Fees for Similar Services to Others DeAM provided management fee schedules for all of its US domiciled
fund and non-fund investment management accounts in any of the
investment categories where there is a DWS Scudder Fund. These similar
products included the other DWS Scudder Funds, non-fund pooled
accounts, institutional accounts and sub-advisory accounts. Using this
information, I calculated for each Fund the fee that would be charged to
each similar product, at the subject Fund's asset level. Evaluating information regarding non-fund products is difficult because
there are varying levels of services required for different types of
accounts, with mutual funds generally requiring considerably more
regulatory and administrative types of service as well as having more
frequent cash flows than other types of accounts. Also, while mutual fund
fees for similar fund products can be expected to be similar, there will be
some differences due to different pricing conditions in different
distribution channels (e.g. retail funds versus those used in variable
insurance products), differences in underlying investment processes and
other factors. Costs and Profit Margins DeAM provided a detailed profitability analysis for each Fund. After
making some adjustments so that the presentation would be more
comparable to the available industry figures, I reviewed profit margins
from investment management alone, from investment management plus
other fund services (excluding distribution) provided to the Funds by
DeAM (principally shareholder services), and DeAM profits from all
sources, including distribution. A later section comments on overall
profitability. Economies of Scale Economies of scale  an expected decline in management cost per dollar
of fund assets as fund assets grow  are very rarely quantified and
documented because of inherent difficulties in collecting and analyzing
relevant data. However, in virtually every investment category that I
reviewed, larger funds tend to have lower fees and lower total expenses
than smaller funds. To see how each DWS Scudder Fund compares with
this industry observation, I reviewed: The trend in Fund assets over the last five years and the accompanying
trend in total expenses. This shows if the Fund has grown and, if so,
whether total expense (management fees as well as other expenses)
have declined as a percent of assets. Whether the Fund has break-points in its management fee schedule,
the extent of the fee reduction built into the schedule and the asset
levels where the breaks take effect, and in the case of a sub-advised
Fund how the Fund's break-points compare with those of the
sub-advisory fee schedule. How the Fund's contractual fee schedule compares with trends in the
industry data. To accomplish this, I constructed a chart showing how
actual latest-fiscal-year contractual fees of the Fund and of other similar
funds relate to average fund assets, with the subject Fund's contractual
fee schedule superimposed. Quality of Service  Performance The quality-of-service evaluation focused on investment performance,
which is the principal result of the investment management service. Each
Fund's performance was reviewed over the past 1, 3, 5 and 10 years, as
applicable, and compared with that of other funds in the same investment
category and with a suitable market index. In addition, I calculated and reviewed risk-adjusted returns relative to an
index of similar mutual funds' returns and a suitable market index. The
risk-adjusted returns analysis provides a way of determining the extent to
which the Fund's return comparisons are mainly the product of investment
value-added (or lack thereof) or alternatively taking considerably more or
less risk than is typical in its investment category. I also received and considered the history of portfolio manager changes
for each Fund, as this provided an important context for evaluating the
performance results. Complex-Level Considerations While this evaluation was conducted mainly at the individual fund level,
there are some issues relating to the reasonableness of fees that can
alternatively be considered across the whole fund complex: I reviewed DeAM's profitability analysis for all DWS Scudder funds,
with a view toward determining if the allocation procedures used were
reasonable and how profit levels compared with public data for other
investment managers. I considered whether DeAM and affiliates receive any significant
ancillary or "fall-out" benefits that should be considered in interpreting
the direct profitability results. These would be situations where serving
as the investment manager of the Funds is beneficial to another part of
the Deutsche Bank organization. I considered how aggregated DWS Scudder Fund expenses had varied
over the years, by asset class and in the context of trends in asset
levels. I reviewed the structure of the DeAM organization, trends in staffing
levels, and information on compensation of investment management
and other professionals compared with industry data. Findings Based on the process and analysis discussed above, which included
reviewing a wide range of information from management and external
data sources and considering among other factors the fees DeAM
charges other clients, the fees charged by other fund managers, DeAM's
costs and profits associated with managing the Funds, economies of
scale, possible fall-out benefits, and the nature and quality of services
provided, in my opinion the management fees charged the DWS Scudder
Funds are reasonable. e500pi_m0Thomas H. Mack Account Management Resources For More
Information
The automated telephone system allows you to access personalized
account information and obtain information on other DWS funds
using either your voice or your telephone keypad. Certain account
types within Class S also have the ability to purchase, exchange or
redeem shares using this system.For more information, contact your financial advisor. You may also
access our automated telephone system or speak with a DWS
Investments representative by calling the appropriate number
below:For shareholders of Institutional Class:
(800) 621-1048For shareholders of Class S:
(800) 728-3337Web Site
www.dws-investments.com
View your account transactions and balances, trade shares, monitor
your asset allocation, and change your address, 24 hours a day.Obtain prospectuses and applications,blank forms, interactive
worksheets, news about DWS funds, subscription to fund updates
by e-mail, retirement planning information, and more.Written
Correspondence
DWS Investments
PO Box 219151
Kansas City, MO 64121-9151Proxy Voting
The fund's policies and procedures for voting proxies for portfolio
securities and information about how the fund voted proxies related
to its portfolio securities during the 12-month period endedJune 30are available on our Web site  www.dws-investments.com (click
on "proxy voting"at the bottom of the page)  or on the SEC's
Web site  www.sec.gov. To obtain a written copy of the fund's
policies and procedures without charge, upon request, call us toll
free at (800) 621-1048.Principal
Underwriter
If you have questions, comments or complaints, contact:DWS Investments Distributors, Inc.
222 South Riverside Plaza
Chicago, IL 60606-5808(800) 621-1148 Class S
Institutional ClassNasdaq Symbol
BTIEX
BTIIXCUSIP Number
23339C 305
23339C 206Fund Number
815
565 Privacy Statement This privacy statement is issued by DWS Investments Distributors, Inc.,
Deutsche Investment Management Americas Inc., DeAM Investor
Services, Inc., DWS Trust Company and the DWS Funds. We never sell customer lists or individual client information. We consider
privacy fundamental to our client relationships and adhere to the
policies and practices described below to protect current and former
clients' information.Internal policies are in place to protect confidentiality,
while allowing client needs to be served. Only individuals who need to do
so in carrying out their job responsibilities may access client information.
We maintain physical, electronic and procedural safeguards that comply
with federal and state standards to protect confidentiality. These
safeguards extend to all forms of interaction with us, including the
Internet. In the normal course of business, clients give us nonpublic personal
information on applications and other forms, on our Web sites, and
through transactions with us or our affiliates. Examples of the nonpublic
personal information collected are name, address, Social Security number
and transaction and balance information. To be able to serve our clients,
certain of this client information is shared with affiliated and nonaffiliated
third-party service providers such as transfer agents, custodians, and
broker-dealers to assist us in processing transactions and servicing your
account with us. In addition, we may disclose all of the information we
collect to companies that perform marketing services on our behalf or
to other financial institutions with which we have joint marketing
agreements. The organizations described above that receive client
information may only use it for the purpose designated by the DWS
Investments Companies listed in the first paragraph of this Privacy
Statement. We may also disclose nonpublic personal information about you to other
parties as required or permitted by law. For example, we are required or
we may provide information to government entities or regulatory bodies in
response to requests for information or subpoenas, to private litigants in
certain circumstances, to law enforcement authorities, or any time we
believe it necessary to protect the firm. Questions on this policy may be sent to: DWS Investments  
Attention: Correspondence  Chicago
P.O. Box 219415
Kansas City, MO  64121-9415 September 2007 e500pi_notesblank0Notes e500pi_backcover0


ITEM 2.
        CODE OF ETHICSNot applicable.ITEM 3.
        AUDIT COMMITTEE FINANCIAL EXPERTNot applicable.ITEM 4.
        PRINCIPAL ACCOUNTANT FEES AND SERVICESNot applicable.
  ITEM 5.
        AUDIT COMMITTEE OF LISTED REGISTRANTSNot ApplicableITEM 6.
        SCHEDULE OF INVESTMENTSNot ApplicableITEM 7.
        DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIESNot applicable.ITEM 8.
        PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIESNot applicable.
  ITEM 9.
        PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY AND AFFILIATED PURCHASERSNot Applicable.
  ITEM 10.
        SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERSThe primary function of the Nominating and Governance Committee is to identify and recommend individuals for membership on the Board and oversee the administration of the Board Governance Guidelines. Shareholders may recommend candidates for Board positions by forwarding their correspondence by U.S. mail or courier service to Chairman of the Board, P.O. Box 100176, Cape Coral, FL 33910.ITEM 11.
        CONTROLS AND PROCEDURES(a)        The Chief Executive and Financial Officers concluded that the Registrants Disclosure Controls and Procedures are effective based on the evaluation of the Disclosure Controls and Procedures as of a date within 90 days of the filing date of this report.(b)        There have been no changes in the registrants internal control over financial reporting that occurred during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrants internal controls over financial reporting.
  
  ITEM 12.
        EXHIBITS(a)(1)   Certification pursuant to Rule 30a-2(a) under the Investment Company Act of 1940 (17 CFR 270.30a-2(a)) is filed and attached hereto as Exhibit 99.CERT.(b)       Certification pursuant to Rule 30a-2(b) under the Investment Company Act of 1940 (17 CFR 270.30a-2(b)) is furnished and attached hereto as Exhibit 99.906CERT.


Form N-CSRS Item F  SIGNATURES  Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.  Registrant:
        DWS Equity 500 Index Fund, a series of DWS Institutional Funds
  By:
        /s/Michael G. Clark
 Michael G. Clark
 President  Date:
        August 26, 2008
   Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.  Registrant:
        DWS Equity 500 Index Fund, a series of DWS Institutional Funds
  By:
        /s/Michael G. Clark
 Michael G. Clark
 President  Date:
        August 26, 2008
   By:
        /s/Paul Schubert
 Paul Schubert
 Chief Financial Officer and Treasurer  Date:
        August 26, 2008