# EDGAR Filing Document

**Accession Number:** 0001107414
**File Stem:** 0001145549-25-038747
**Filing Date:** 2025-6
**Character Count:** 13327
**Document Hash:** 54e6f7d80877d8467db4f69a39f27ca9
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001145549-25-038747.hdr.sgml**: 20250606

**ACCESSION NUMBER**: 0001145549-25-038747

**CONFORMED SUBMISSION TYPE**: N-MFP3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250531

**FILED AS OF DATE**: 20250606

**DATE AS OF CHANGE**: 20250606

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** STATE STREET INSTITUTIONAL INVESTMENT TRUST
- **CENTRAL INDEX KEY:** 0001107414

**ORGANIZATION NAME:**
- **EIN:** 046910804
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** N-MFP3
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-09819
- **FILM NUMBER:** 251029156

**BUSINESS ADDRESS:**
- **STREET 1:** ONE IRON STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02210
- **BUSINESS PHONE:** 6176643920

**MAIL ADDRESS:**
- **STREET 1:** ONE IRON STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02210

## Series and Classes Contracts Data

### State Street Treasury Obligations Money Market Fund (Series ID: S000058519)

| Class ID   | Class Name                                          | Ticker Symbol   |
|:---|:---|:---|
| C000192374 | State Street Treasury Obligations Money Market Fund | TAQXX           |

# Form N-MFP3: Monthly Schedule of Portfolio Holdings

## N-MFP: Filer Information
**Submission Type:** N-MFP3
**CIK:** 0001107414

### General Information

**Report for (YYYY-MM-DD):** 2025-05-31

**Registrant Full Name:** STATE STREET INSTITUTIONAL INVESTMENT TRUST

**CIK Number of Registrant:** 0001107414

**LEI of Registrant:** 549300P1E098W6ES7M39

**Name of Series:** State Street Treasury Obligations Money Market Fund

**LEI of Series:** 549300Q6TZ3O71NFFG47

**EDGAR Series Identifier:** S000058519

**Total number of share classes in the series:** 1

**Is this the fund's final filing on Form N-MFP?:** No

**Has the fund acquired or merged with another fund?:** No

## Part A: Series-Level Information about the Fund

### Service Providers
| Role                          | Details                                         | File/CIK Number   |
|:---|:---|:---|
| Investment Adviser            | SSGA Funds Management, Inc.                     | 801-60103         |
| Independent Public Accountant | Ernst & Young  LLP<br>City: Boston<br>State: MA |  |
| Administrator                 | SSGA Funds Management, Inc.                     |  |
| Transfer Agent                | SS&C GIDS, Inc.<br>CIK: 0000027048              | 084-00448         |

### Fund Characteristics & Assets

- **Securities Act File Number:** 333-30810

- **Is this a Feeder Fund?:** Yes

- **Is this a Master Fund?:** No

- **Is this series for insurance company separate accounts?:** No

- **Money Market Fund Category:** Government

- **Is this a Retail Money Market Fund?:** No

- **Is this a Government Money Market Fund?:** No

- **WAM:** 1 days

- **WAL:** 1 days

- **Total Value of Portfolio Securities:** $4430504453.02

- **Amortized Cost of Portfolio Securities:** $4430504453.02

- **Cash:** $0.00

- **Total Other Assets:** $0.00

- **Total Liabilities:** $19049935.23

- **Net Assets of Series:** $4411454517.79

- **Number of Shares Outstanding (Series):** 4411527300.8800

- **Does the fund seek to maintain a stable price per share?:** Yes

- **Stable Price Per Share:** $1.00

- **Is cash management vehicle an affiliated fund?:** No

- **Does the fund apply liquidity fees?:** No

### Daily & Weekly Liquid Assets
| Date       | Daily Liquid Assets ($)   | Weekly Liquid Assets ($)   | Daily Liquid Assets (%)   | Weekly Liquid Assets (%)   |
|:---|:---|:---|:---|:---|
| 2025-05-01 | $57680503649.20           | $58445503649.20            | 96.1000%                  | 97.3800%                   |
| 2025-05-02 | $57609263959.76           | $58514263959.76            | 95.8600%                  | 97.3600%                   |
| 2025-05-05 | $57733155112.21           | $58638155112.21            | 95.8700%                  | 97.3800%                   |
| 2025-05-06 | $56365936959.77           | $57135936959.77            | 95.1900%                  | 96.4900%                   |
| 2025-05-07 | $57213574475.48           | $57353574475.48            | 96.2600%                  | 96.5000%                   |
| 2025-05-08 | $56344824611.45           | $56974824611.45            | 95.4100%                  | 96.4700%                   |
| 2025-05-09 | $56521362013.20           | $57491362013.20            | 95.1800%                  | 96.8100%                   |
| 2025-05-12 | $58067276597.88           | $59037276597.88            | 95.3100%                  | 96.9000%                   |
| 2025-05-13 | $57571275421.29           | $58541275421.29            | 95.2700%                  | 96.8700%                   |
| 2025-05-14 | $57391377625.45           | $57731377625.45            | 96.2600%                  | 96.8300%                   |
| 2025-05-15 | $58252407566.55           | $58652407566.55            | 96.2200%                  | 96.8800%                   |
| 2025-05-16 | $57745240973.09           | $58485240973.09            | 95.3200%                  | 96.5400%                   |
| 2025-05-19 | $57498381515.85           | $58238381515.85            | 95.3000%                  | 96.5300%                   |
| 2025-05-20 | $56689104216.69           | $57429104216.69            | 95.2400%                  | 96.4800%                   |
| 2025-05-21 | $56614354231.46           | $56954354231.46            | 95.8800%                  | 96.4500%                   |
| 2025-05-22 | $55493629993.53           | $55493629993.53            | 96.3600%                  | 96.3600%                   |
| 2025-05-23 | $55433687066.63           | $55633687066.63            | 96.0000%                  | 96.3500%                   |
| 2025-05-27 | $55486489033.72           | $55936489033.72            | 96.0200%                  | 96.7900%                   |
| 2025-05-28 | $57451284784.87           | $57901284784.87            | 96.1500%                  | 96.9000%                   |
| 2025-05-29 | $56758175269.90           | $57008175269.90            | 96.4200%                  | 96.8500%                   |
| 2025-05-30 | $56444949431.93           | $56894949431.93            | 96.0600%                  | 96.8300%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2025-05-01 | 4.3900%             |
| 2025-05-02 | 4.3800%             |
| 2025-05-05 | 4.3800%             |
| 2025-05-06 | 4.3700%             |
| 2025-05-07 | 4.3700%             |
| 2025-05-08 | 4.3600%             |
| 2025-05-09 | 4.3500%             |
| 2025-05-12 | 4.3500%             |
| 2025-05-13 | 4.3500%             |
| 2025-05-14 | 4.3500%             |
| 2025-05-15 | 4.3500%             |
| 2025-05-16 | 4.3600%             |
| 2025-05-19 | 4.3600%             |
| 2025-05-20 | 4.3600%             |
| 2025-05-21 | 4.3600%             |
| 2025-05-22 | 4.3500%             |
| 2025-05-23 | 4.3500%             |
| 2025-05-27 | 4.3500%             |
| 2025-05-28 | 4.3500%             |
| 2025-05-29 | 4.3500%             |
| 2025-05-30 | 4.3700%             |

### Daily Net Asset Value per Share (Series)
| Date       | Net Asset Value per Share   |
|:---|:---|
| 2025-05-01 | 1.0000                      |
|  |  |
| 2025-05-02 | 1.0000                      |
|  |  |
| 2025-05-05 | 1.0000                      |
|  |  |
| 2025-05-06 | 1.0001                      |
|  |  |
| 2025-05-07 | 1.0001                      |
|  |  |
| 2025-05-08 | 1.0000                      |
|  |  |
| 2025-05-09 | 1.0000                      |
|  |  |
| 2025-05-12 | 1.0000                      |
|  |  |
| 2025-05-13 | 1.0000                      |
|  |  |
| 2025-05-14 | 1.0000                      |
|  |  |
| 2025-05-15 | 1.0000                      |
|  |  |
| 2025-05-16 | 1.0000                      |
|  |  |
| 2025-05-19 | 1.0000                      |
|  |  |
| 2025-05-20 | 1.0000                      |
|  |  |
| 2025-05-21 | 1.0000                      |
|  |  |
| 2025-05-22 | 1.0000                      |
|  |  |
| 2025-05-23 | 1.0000                      |
|  |  |
| 2025-05-27 | 1.0000                      |
|  |  |
| 2025-05-28 | 1.0000                      |
|  |  |
| 2025-05-29 | 1.0000                      |
|  |  |
| 2025-05-30 | 1.0000                      |
|  |  |

## Part B: Class-Level Information about the Fund

### Class: A

- **Minimum Initial Investment:** $1000000000.00

- **Net Assets of Class:** $4411454517.79

- **Number of Shares Outstanding:** 4411527300.8800

- **Expense Reimbursement/Waiver:** 132440.00

**Daily Net Asset Value per Share (Class)**
| Date       | NAV per Share   |
|:---|:---|
| 2025-05-01 | 1.0000          |
|  |  |
| 2025-05-02 | 1.0000          |
|  |  |
| 2025-05-05 | 1.0000          |
|  |  |
| 2025-05-06 | 1.0001          |
|  |  |
| 2025-05-07 | 1.0001          |
|  |  |
| 2025-05-08 | 1.0000          |
|  |  |
| 2025-05-09 | 1.0000          |
|  |  |
| 2025-05-12 | 1.0000          |
|  |  |
| 2025-05-13 | 1.0000          |
|  |  |
| 2025-05-14 | 1.0000          |
|  |  |
| 2025-05-15 | 1.0000          |
|  |  |
| 2025-05-16 | 1.0000          |
|  |  |
| 2025-05-19 | 1.0000          |
|  |  |
| 2025-05-20 | 1.0000          |
|  |  |
| 2025-05-21 | 1.0000          |
|  |  |
| 2025-05-22 | 1.0000          |
|  |  |
| 2025-05-23 | 1.0000          |
|  |  |
| 2025-05-27 | 1.0000          |
|  |  |
| 2025-05-28 | 1.0000          |
|  |  |
| 2025-05-29 | 1.0000          |
|  |  |
| 2025-05-30 | 1.0000          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2025-05-01 | $41246781.45              | $20623143.10            |
| 2025-05-02 | $15.38                    | $0.00                   |
| 2025-05-05 | $0.00                     | $500000000.00           |
| 2025-05-06 | $0.00                     | $275754332.00           |
| 2025-05-07 | $549389063.00             | $377672725.00           |
| 2025-05-08 | $0.00                     | $5914055.00             |
| 2025-05-09 | $0.00                     | $5022591.00             |
| 2025-05-12 | $0.00                     | $2468104.00             |
| 2025-05-13 | $0.00                     | $343531222.00           |
| 2025-05-14 | $92473023.00              | $966337357.00           |
| 2025-05-15 | $5.00                     | $0.00                   |
| 2025-05-16 | $0.00                     | $7766367.00             |
| 2025-05-20 | $603513112.00             | $173326726.00           |
| 2025-05-22 | $531939167.00             | $107874236.00           |
| 2025-05-23 | $0.00                     | $3062876.00             |
| 2025-05-27 | $0.00                     | $39105344.00            |
| 2025-05-28 | $0.00                     | $25808007.00            |
| 2025-05-29 | $0.00                     | $547606412.00           |
| 2025-05-30 | $0.00                     | $38111564.00            |

**Total Gross Subscriptions (Month):** $1818561166.83

**Total Gross Redemptions (Month):** $3439985061.10

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2025-05-01 | 4.3100%           |
| 2025-05-02 | 4.3000%           |
| 2025-05-05 | 4.3000%           |
| 2025-05-06 | 4.2900%           |
| 2025-05-07 | 4.2900%           |
| 2025-05-08 | 4.2800%           |
| 2025-05-09 | 4.2700%           |
| 2025-05-12 | 4.2700%           |
| 2025-05-13 | 4.2700%           |
| 2025-05-14 | 4.2700%           |
| 2025-05-15 | 4.2700%           |
| 2025-05-16 | 4.2800%           |
| 2025-05-19 | 4.2800%           |
| 2025-05-20 | 4.2800%           |
| 2025-05-21 | 4.2800%           |
| 2025-05-22 | 4.2700%           |
| 2025-05-23 | 4.2700%           |
| 2025-05-27 | 4.2700%           |
| 2025-05-28 | 4.2700%           |
| 2025-05-29 | 4.2700%           |
| 2025-05-30 | 4.2900%           |

**Beneficial/Record Owner Categories**
| Category                  | Other Category   | Record Owner %   | Beneficial Owner %   |
|:---|:---|:---|:---|
| Non-financial corporation |  | 99.9900%         | 0.0000%              |

## Part C: Schedule of Portfolio Securities

### Security 1: State Street Treasury Plus Money Market Portfolio

- **C.1 - Title:** State Street Treasury Plus Money Market Portfolio
- **C.6 - Investment Category:** Investment Company
- **Identifiers:** C.3 - CUSIP: FSSgAK183, C.3 - LEI: N/A, C.5 - Other ID: FSSgAK183
- **C.18 - Value (incl. sponsor support):** $4430504453.02
- **C.18.a - Value (excl. sponsor support):** $4430504453.02
- **C.19 - Percentage of Net Assets:** 100.0000%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2025-06-02
- **C.12 - Maturity Date (WAL):** 2025-06-02
- **C.13 - Final Legal Maturity Date:** 2025-06-02
- **Characteristics:** C.9 Eligible Security? Yes, C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

## N-MFP: Signatures

**Registrant:** STATE STREET INSTITUTIONAL INVESTMENT TRUST

**Date:** 2025-06-06

**By:** /s/ Chad Hallett

**Name of Signing Officer:** Chad Hallett

**Title of Signing Officer:** Deputy Treasurer