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                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 10-Q

   X     QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES 
-------  EXCHANGE ACT OF 1934

FOR THE QUARTERLY PERIOD ENDED:  JUNE 30, 1998

                                       OR

         TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES 
-------  EXCHANGE ACT OF 1934

FOR THE TRANSITION PERIOD FROM ____________ TO ______________

COMMISSION FILE NUMBER:  33-47912

                          CMC SECURITIES CORPORATION IV
             (Exact name of Registrant as specified in its Charter)

         DELAWARE                                              75-2431915
(State or other jurisdiction of                             (I.R.S. Employer
incorporation or organization)                             Identification No.)

  2711 NORTH HASKELL, DALLAS, TEXAS                                75204
(Address of principal executive offices)                         (Zip Code)

        Registrant's telephone number, including area code (214) 874-2323

The Registrant meets the conditions set forth in General Instruction H(1)(a) and
(b) for Form 10-Q and is therefore filing this Form under the reduced disclosure
format.

Indicate by check mark whether the Registrant (1) has filed all documents and
reports required to be filed by Section 13 or 15(d) of the Securities Exchange
Act of 1934 during the preceding 12 months (or for such shorter period that the
Registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days. YES X   NO
                                             ----   ----

                      APPLICABLE ONLY TO CORPORATE ISSUERS:

Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the last practicable date.

Common Stock ($1.00 par value)                       1,000 as of August 12, 1998

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                          CMC SECURITIES CORPORATION IV
                                    FORM 10-Q
                       FOR THE QUARTER ENDED JUNE 30, 1998


                                      INDEX



                        PART I. -- FINANCIAL INFORMATION

<TABLE>
<CAPTION>


                                                                                                           PAGE

<S>                                                                                                       <C>

ITEM 1.       Financial Statements

   Balance Sheet -- June 30, 1998 (Unaudited) and December 31, 1997....................................     1

   Statement of Operations - Quarter and Six Months
     Ended June 30, 1998 and 1997 (Unaudited)..........................................................     2

   Statement of Cash Flows - Six Months Ended
     June 30, 1998 and 1997 (Unaudited)................................................................     3

   Notes to Financial Statements (Unaudited)...........................................................     4

ITEM 2.       Management's Discussion and Analysis of
              Financial Condition and Results of Operations............................................     6


                                           PART II. -- OTHER INFORMATION


ITEM 6.       Exhibits and Reports on Form 8-K.........................................................     6

SIGNATURES.............................................................................................     7
</TABLE>


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                          CMC SECURITIES CORPORATION IV
                        PART I. -- FINANCIAL INFORMATION
                                  BALANCE SHEET
                      (IN THOUSANDS, EXCEPT PER SHARE DATA)



ITEM 1.       FINANCIAL STATEMENTS

<TABLE>
<CAPTION>


                                                 JUNE 30, 1998    DECEMBER 31, 1997
                                                ---------------   -----------------
                                                  (UNAUDITED)

<S>                                             <C>                <C>            
ASSETS
   Mortgage securities collateral               $     1,474,199    $     1,728,030
   Cash and cash equivalents                                  1                  2
                                                ---------------    ---------------

                                                $     1,474,200    $     1,728,032
                                                ===============    ===============

LIABILITIES
   Collateralized mortgage securities           $     1,474,020    $     1,727,766
   Accrued expenses                                          38                 32
                                                ---------------    ---------------

                                                      1,474,058          1,727,798
                                                ---------------    ---------------

STOCKHOLDER'S EQUITY
   Common stock - $1.00 par value,
     1 shares authorized,
     issued and outstanding                                   1                  1
   Paid-in capital                                          454                490
   Accumulated deficit                                     (313)              (257)
                                                ---------------    ---------------

                                                            142                234
                                                ---------------    ---------------

                                                $     1,474,200    $     1,728,032
                                                ===============    ===============
</TABLE>


See accompanying notes to financial statements.


                                      -1-

<PAGE>   4



                          CMC SECURITIES CORPORATION IV
                             STATEMENT OF OPERATIONS
                                   (UNAUDITED)
                                 (IN THOUSANDS)

<TABLE>
<CAPTION>



                                                 QUARTER ENDED             SIX MONTHS ENDED
                                                    JUNE 30                    JUNE 30
                                           ------------------------    ------------------------
                                              1998          1997          1998          1997
                                           ----------    ----------    ----------    ----------

<S>                                        <C>           <C>           <C>           <C>       
Interest income on
   mortgage securities collateral          $   30,478    $   12,281    $   62,778    $   25,221

Interest expenses on collateralized
   mortgage securities                         30,496        12,303        62,816        25,265
                                           ----------    ----------    ----------    ----------

       Net interest expense                       (18)          (22)          (38)          (44)
                                           ----------    ----------    ----------    ----------

Other expenses:
   Management fees                                  2             2             5             5
   Professional fees and other                      4             3            13            11
                                           ----------    ----------    ----------    ----------

     Total other expenses                           6             5            18            16
                                           ----------    ----------    ----------    ----------

Net loss                                   $      (24)   $      (27)   $      (56)   $      (60)
                                           ==========    ==========    ==========    ==========

</TABLE>


See accompanying notes to financial statements.

                                      -2-


<PAGE>   5



                         CMC SECURITIES CORPORATION IV
                            STATEMENT OF CASH FLOWS
                                  (UNAUDITED)
                                 (IN THOUSANDS)

<TABLE>
<CAPTION>




                                                 SIX MONTHS ENDED JUNE 30
                                                 ------------------------
                                                    1998          1997
                                                 ----------    ----------

<S>                                              <C>           <C>        
OPERATING ACTIVITIES:
   Net loss                                      $      (56)   $      (60)
   Net change in other assets and
     accrued expenses                                     6             6
   Noncash item - amortization of
     discount and premium                                53            33
                                                 ----------    ----------
       Net cash provided (used) by
         operating activities                             3           (21)
                                                 ----------    ----------

INVESTING ACTIVITIES:
   Mortgage securities collateral:
     Principal collections on collateral            254,951        32,095
     Decrease in accrued interest receivable          1,800           198
                                                 ----------    ----------
       Net cash provided by
         investing activities                       256,751        32,293
                                                 ----------    ----------

FINANCING ACTIVITIES:
   Collateralized mortgage securities:
     Principal payments on securities              (254,951)      (32,095)
     Decrease in accrued interest payable            (1,768)         (187)
   Capital contribution (distribution)                  (36)           10
                                                 ----------    ----------
       Net cash used by financing
         activities                                (256,755)      (32,272)
                                                 ----------    ----------

Net change in cash and cash equivalents                  (1)           --

Cash and cash equivalents at beginning
   of period                                              2            --
                                                 ----------    ----------

Cash and cash equivalents at end of
   period                                        $        1    $       --
                                                 ==========    ==========

</TABLE>


See accompanying notes to financial statements.


                                      -3-

<PAGE>   6



                          CMC SECURITIES CORPORATION IV
                          NOTES TO FINANCIAL STATEMENTS
                                  JUNE 30, 1998
                                   (UNAUDITED)


NOTE A -- BASIS OF PRESENTATION

The accompanying unaudited financial statements have been prepared in accordance
with generally accepted accounting principles for interim financial information
and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X.
Accordingly, they do not include all of the information and footnotes required
by generally accepted accounting principles for complete financial statements.
In the opinion of management, all adjustments (consisting of normal recurring
accruals) considered necessary for a fair presentation have been included.
Operating results for the quarter and six months ended June 30, 1998 are not
necessarily indicative of the results that may be expected for the year ended
December 31, 1998. For further information refer to the financial statements and
footnotes thereto included in the CMC Securities Corporation IV annual report on
Form 10-K for the year ended December 31, 1997.

NOTE B -- DISCLOSURES REGARDING FAIR VALUES OF MORTGAGE SECURITIES COLLATERAL

The estimated fair values of mortgage securities collateral have been determined
by using available market information and appropriate valuation methodologies;
however, considerable judgment is required in interpreting market data to
develop these estimates. In addition, fair values fluctuate on a daily basis.
Accordingly, the estimates presented herein are not necessarily indicative of
the amounts that could be realized in a current market exchange. The use of
different market assumptions and/or estimation methodologies may have a material
effect on the estimated fair value amounts.

The fair values of mortgage securities collateral were estimated using quoted
market prices, when available, including quotes made by Capstead Mortgage
Corporation's lenders in connection with designating collateral for repurchase
arrangements.

The following table summarizes the fair values of mortgage securities collateral
(in thousands):

<TABLE>
<CAPTION>


                                          JUNE 30, 1998      DECEMBER 31, 1997
                                          -------------      -----------------


<S>                                        <C>                 <C>         
Carrying amount                            $  1,474,199        $  1,728,030
Unrealized gains                                 56,406              63,115
                                           ------------        ------------

  Fair value                               $  1,530,605        $  1,791,145
                                           ============        ============

</TABLE>


All mortgage securities collateral is held-to-maturity. The maturity of mortgage
securities collateral is directly affected by the rate of principal prepayments
by mortgagors. In addition, upon the redemption of remaining bonds outstanding
pursuant to clean-up calls, released collateral may be sold. Such sales are
deemed maturities under the provisions of Statement of Financial Accounting
Standards No. 115. No such redemptions have occurred.








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<PAGE>   7
NOTE C -- NET INTEREST INCOME ANALYSIS

The following tables summarize the amount of interest income and interest
expense and the average effective interest rates for mortgage securities
collateral and collateralized mortgage securities (dollars in thousands):

<TABLE>
<CAPTION>
                                                            QUARTER ENDED JUNE 30
                                                --------------------------------------------
                                                        1998                    1997
                                                ---------------------    -------------------
                                                              AVERAGE                AVERAGE
                                                 AMOUNT        RATE       AMOUNT      RATE
                                                --------     --------    --------   --------
<S>                                             <C>             <C>      <C>            <C>  
Interest income on mortgage
   securities collateral                        $ 30,478        7.98%    $ 12,281       8.43%
Interest expense on
   collateralized mortgage securities             30,496        7.98       12,303       8.45
                                                --------                 --------

Net interest                                    $    (18)                $    (22)
                                                ========                 ========
</TABLE>


<TABLE>
<CAPTION>
                                                           SIX MONTHS ENDED JUNE 30
                                                --------------------------------------------
                                                        1998                   1997
                                                ---------------------    -------------------
                                                              AVERAGE                AVERAGE
                                                 AMOUNT        RATE       AMOUNT      RATE
                                                --------     --------    --------   --------
<S>                                             <C>             <C>      <C>            <C>  
Interest income on mortgage
   securities collateral                        $ 62,778        7.87%    $ 25,221       8.55%
Interest expense on
   collateralized mortgage securities             62,816        7.88       25,265       8.57
                                                --------                 --------   

Net interest                                    $    (38)                $    (44)
                                                ========                 ========

</TABLE>


The following tables summarize changes in interest income and interest expense
due to changes in interest rates, versus changes in volume for the quarter and
six months ended June 30, 1998, compared to the same periods in 1997 (in
thousands):

<TABLE>
<CAPTION>
                                                  QUARTER ENDED JUNE 30, 1998
                                                --------------------------------
                                                  RATE *     VOLUME*     TOTAL
                                                --------    --------    --------
<S>                                             <C>         <C>         <C>     
Interest income on mortgage
   securities collateral                        $   (697)   $ 18,894    $ 18,197
Interest expense on
   collateralized mortgage securities               (718)     18,911      18,193
                                                --------    --------    --------

                                                $     21    $    (17)   $      4
                                                ========    ========    ========

</TABLE>


<TABLE>
<CAPTION>
                                                 SIX MONTHS ENDED JUNE 30, 1998
                                                --------------------------------
                                                  RATE*     VOLUME*      TOTAL
                                                --------    --------    --------
<S>                                             <C>         <C>         <C>     
Interest income on mortgage
   securities collateral                        $ (2,157)   $ 39,714    $ 37,557
Interest expense on
   collateralized mortgage securities             (2,197)     39,748      37,551
                                                --------    --------    --------

                                                $     40    $    (34)   $      6
                                                ========    ========    ========

</TABLE>


*    THE CHANGES IN INTEREST INCOME AND EXPENSE DUE TO BOTH VOLUME AND RATE HAVE
     BEEN ALLOCATED TO VOLUME AND RATE CHANGES IN PROPORTION TO THE RELATIONSHIP
     OF THE ABSOLUTE DOLLAR AMOUNTS OF THE CHANGE IN EACH.



                                      -5-


<PAGE>   8



ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
         OF OPERATIONS


FINANCIAL CONDITION AND RESULTS OF OPERATIONS

CMC Securities Corporation IV (the "Company") was incorporated in Delaware on
May 6, 1992 as a limited purpose finance corporation, and is a wholly-owned
subsidiary of Capstead Mortgage Corporation ("CMC").

As of October 31, 1997, the Company had issued 5 series of collateralized
mortgage obligations ("CMOs") with an aggregate original principal balance of
$2,003,125,000; $176,304,000 of which was issued through private placements,
with the remainder being issued under the registration statement. These
issuances have been accounted for as financings. The Company has essentially
issued the maximum amount of securities under the $2 billion amended
registration statement; therefore, the Company has not issued any CMOs since
October 31, 1997. Since the Company did not retain any investment in the CMOs
issued, no economic benefit was or will be received, thus no net income or loss
was or will be recognized, other than amortization of unreimbursed shelf
issuance costs.

The Company's net losses are due to operational costs incurred (management and
professional fees) and unreimbursed shelf registration costs.

LIQUIDITY AND CAPITAL RESOURCES

All ongoing CMO expenses of the Company are paid out of the excess cash flows on
the CMOs issued before the residual holders receive their residual interest. The
Company believes that the excess cash flows will be sufficient to pay ongoing
CMO expenses. Cash flow requirements due to ongoing operational costs are funded
by CMC.


                          PART II. -- OTHER INFORMATION


ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K:

(a)      Exhibits:

         Exhibit 27 Financial Data Schedule (electronic filing only).

(b)      Reports on Form 8-K:  None.









                                      -6-

<PAGE>   9



                                   SIGNATURES


Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.


                                  CMC SECURITIES CORPORATION IV




Date:  August 12, 1998                By:  /s/ RONN K. LYTLE
                                           -------------------------------------
                                           Ronn K. Lytle
                                           Chairman and Chief Executive Officer




Date:  August 12, 1998                By:  /s/ ANDREW F. JACOBS
                                           -------------------------------------
                                           Andrew F. Jacobs
                                           Executive Vice President - Finance,
                                             Treasurer and Secretary




                                       -7-

<PAGE>   10
                               INDEX TO EXHIBITS





<TABLE>
<CAPTION>
EXHIBIT
NUMBER                              DESCRIPTION
-------                            -----------
<S>                         <C>

  27                        Financial Data Schedule
</TABLE>