# EDGAR Filing Document

**Accession Number:** 0001107414
**File Stem:** 0001410368-26-042643
**Filing Date:** 2026-5
**Character Count:** 13753
**Document Hash:** ce3ae47a08c619f00b49df984257d174
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001410368-26-042643.hdr.sgml**: 20260507

**ACCESSION NUMBER**: 0001410368-26-042643

**CONFORMED SUBMISSION TYPE**: N-MFP3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260430

**FILED AS OF DATE**: 20260507

**DATE AS OF CHANGE**: 20260507

**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:** 26951455

**BUSINESS ADDRESS:**
- **STREET 1:** ONE CONGRESS STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02114
- **BUSINESS PHONE:** 6176643920

**MAIL ADDRESS:**
- **STREET 1:** ONE CONGRESS STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02114

## Series and Classes Contracts Data

### State Street Federal Government Money Market Fund (Series ID: S000086383)

| Class ID   | Class Name      | Ticker Symbol   |
|:---|:---|:---|
| C000251886 | Advantage Class | AGFXX           |

# 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):** 2026-04-30

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

**CIK Number of Registrant:** 0001107414

**LEI of Registrant:** 549300P1E098W6ES7M39

**Name of Series:** State Street Federal Government Money Market Fund

**LEI of Series:** 98450099C3D5363FC713

**EDGAR Series Identifier:** S000086383

**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:** $185384735.17

- **Amortized Cost of Portfolio Securities:** $185384735.17

- **Cash:** $0.00

- **Total Other Assets:** $0.00

- **Total Liabilities:** $835188.03

- **Net Assets of Series:** $184549547.14

- **Number of Shares Outstanding (Series):** 184549239.4000

- **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 (%)   |
|:---|:---|:---|:---|:---|
| 2026-04-01 | $181110465074.13          | $181349528062.53           | 84.8900%                  | 85.0000%                   |
| 2026-04-02 | $176686552338.19          | $178415645668.44           | 84.1900%                  | 85.0100%                   |
| 2026-04-03 | $0.00                     | $0.00                      | 0.0000%                   | 0.0000%                    |
| 2026-04-06 | $180170816507.46          | $181899994172.32           | 84.4500%                  | 85.2600%                   |
| 2026-04-07 | $185180885393.24          | $186796542593.30           | 84.8500%                  | 85.5900%                   |
| 2026-04-08 | $187259089915.04          | $188124862078.79           | 85.2900%                  | 85.6800%                   |
| 2026-04-09 | $186999168239.41          | $187969645724.77           | 85.2600%                  | 85.7100%                   |
| 2026-04-10 | $179305918019.23          | $180276405171.40           | 84.4200%                  | 84.8800%                   |
| 2026-04-13 | $180898093758.97          | $182803616825.34           | 84.5000%                  | 85.3900%                   |
| 2026-04-14 | $181251768108.89          | $182222202906.89           | 84.3700%                  | 84.8200%                   |
| 2026-04-15 | $180394195207.08          | $180519942157.50           | 84.6500%                  | 84.7100%                   |
| 2026-04-16 | $173828371489.25          | $174704130758.69           | 83.6500%                  | 84.0700%                   |
| 2026-04-17 | $166901993298.25          | $167831165170.97           | 82.9500%                  | 83.4100%                   |
| 2026-04-20 | $168708369241.76          | $170087142316.95           | 82.4700%                  | 83.1500%                   |
| 2026-04-21 | $166571683495.30          | $167950480450.83           | 82.1100%                  | 82.7900%                   |
| 2026-04-22 | $162002801061.93          | $162631618665.00           | 82.0100%                  | 82.3200%                   |
| 2026-04-23 | $159149808887.52          | $159725246180.10           | 81.7600%                  | 82.0600%                   |
| 2026-04-24 | $154289493703.91          | $154989949911.13           | 81.4400%                  | 81.8100%                   |
| 2026-04-27 | $159382623225.86          | $160083140736.58           | 81.8800%                  | 82.2400%                   |
| 2026-04-28 | $168743383697.25          | $169443920497.25           | 82.7100%                  | 83.0500%                   |
| 2026-04-29 | $168637636153.86          | $169338193564.61           | 82.7000%                  | 83.0400%                   |
| 2026-04-30 | $166794140298.74          | $167557119881.20           | 82.7700%                  | 83.1500%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2026-04-01 | 3.7200%             |
| 2026-04-02 | 3.7200%             |
| 2026-04-03 | 0.0000%             |
| 2026-04-06 | 3.7100%             |
| 2026-04-07 | 3.7100%             |
| 2026-04-08 | 3.7100%             |
| 2026-04-09 | 3.7000%             |
| 2026-04-10 | 3.6900%             |
| 2026-04-13 | 3.6900%             |
| 2026-04-14 | 3.6900%             |
| 2026-04-15 | 3.7000%             |
| 2026-04-16 | 3.7000%             |
| 2026-04-17 | 3.7200%             |
| 2026-04-20 | 3.7200%             |
| 2026-04-21 | 3.7200%             |
| 2026-04-22 | 3.7100%             |
| 2026-04-23 | 3.7100%             |
| 2026-04-24 | 3.7200%             |
| 2026-04-27 | 3.7200%             |
| 2026-04-28 | 3.7200%             |
| 2026-04-29 | 3.7200%             |
| 2026-04-30 | 3.7200%             |

### Daily Net Asset Value per Share (Series)
| Date       | Net Asset Value per Share   |
|:---|:---|
| 2026-04-01 | 0.9999                      |
|  |  |
| 2026-04-02 | 0.9999                      |
|  |  |
| 2026-04-03 | 0.0000                      |
|  |  |
| 2026-04-06 | 0.9999                      |
|  |  |
| 2026-04-07 | 1.0000                      |
|  |  |
| 2026-04-08 | 0.9999                      |
|  |  |
| 2026-04-09 | 1.0000                      |
|  |  |
| 2026-04-10 | 1.0000                      |
|  |  |
| 2026-04-13 | 1.0000                      |
|  |  |
| 2026-04-14 | 1.0000                      |
|  |  |
| 2026-04-15 | 1.0000                      |
|  |  |
| 2026-04-16 | 1.0000                      |
|  |  |
| 2026-04-17 | 1.0000                      |
|  |  |
| 2026-04-20 | 1.0000                      |
|  |  |
| 2026-04-21 | 0.9999                      |
|  |  |
| 2026-04-22 | 1.0000                      |
|  |  |
| 2026-04-23 | 1.0000                      |
|  |  |
| 2026-04-24 | 1.0000                      |
|  |  |
| 2026-04-27 | 1.0000                      |
|  |  |
| 2026-04-28 | 1.0000                      |
|  |  |
| 2026-04-29 | 0.9999                      |
|  |  |
| 2026-04-30 | 1.0000                      |
|  |  |

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

### Class: Advantage Class

- **Minimum Initial Investment:** $1000000.00

- **Net Assets of Class:** $184549547.14

- **Number of Shares Outstanding:** 184549239.4000

- **Expense Reimbursement/Waiver:** 10254.00

**Daily Net Asset Value per Share (Class)**
| Date       | NAV per Share   |
|:---|:---|
| 2026-04-01 | 0.9999          |
|  |  |
| 2026-04-02 | 0.9999          |
|  |  |
| 2026-04-03 | 0.0000          |
|  |  |
| 2026-04-06 | 0.9999          |
|  |  |
| 2026-04-07 | 1.0000          |
|  |  |
| 2026-04-08 | 0.9999          |
|  |  |
| 2026-04-09 | 1.0000          |
|  |  |
| 2026-04-10 | 1.0000          |
|  |  |
| 2026-04-13 | 1.0000          |
|  |  |
| 2026-04-14 | 1.0000          |
|  |  |
| 2026-04-15 | 1.0000          |
|  |  |
| 2026-04-16 | 1.0000          |
|  |  |
| 2026-04-17 | 1.0000          |
|  |  |
| 2026-04-20 | 1.0000          |
|  |  |
| 2026-04-21 | 0.9999          |
|  |  |
| 2026-04-22 | 1.0000          |
|  |  |
| 2026-04-23 | 1.0000          |
|  |  |
| 2026-04-24 | 1.0000          |
|  |  |
| 2026-04-27 | 1.0000          |
|  |  |
| 2026-04-28 | 1.0000          |
|  |  |
| 2026-04-29 | 0.9999          |
|  |  |
| 2026-04-30 | 1.0000          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2026-04-01 | $1824994.71               | $477651.65              |
| 2026-04-02 | $2138046.73               | $430506.91              |
| 2026-04-03 | $0.00                     | $0.00                   |
| 2026-04-06 | $710000.00                | $3243275.96             |
| 2026-04-07 | $365900.00                | $2210158.64             |
| 2026-04-08 | $736498.78                | $824730.94              |
| 2026-04-09 | $987438.35                | $1477040.76             |
| 2026-04-10 | $503133.51                | $934021.16              |
| 2026-04-13 | $262182.00                | $1071871.43             |
| 2026-04-14 | $940733.00                | $785683.07              |
| 2026-04-15 | $748200.00                | $561709.02              |
| 2026-04-16 | $779444.29                | $894362.49              |
| 2026-04-17 | $573677.89                | $571464.06              |
| 2026-04-20 | $1042225.65               | $199697.54              |
| 2026-04-21 | $1932880.00               | $625017.82              |
| 2026-04-22 | $259350.00                | $1075950.04             |
| 2026-04-23 | $741212.03                | $769210.00              |
| 2026-04-24 | $376550.00                | $386860.00              |
| 2026-04-27 | $441755.00                | $226986.27              |
| 2026-04-28 | $372365.00                | $781428.98              |
| 2026-04-29 | $1131065.00               | $365792.00              |
| 2026-04-30 | $868245.00                | $409024.69              |

**Total Gross Subscriptions (Month):** $17735896.94

**Total Gross Redemptions (Month):** $18322443.43

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2026-04-01 | 3.3300%           |
| 2026-04-02 | 3.3300%           |
| 2026-04-03 | 0.0000%           |
| 2026-04-06 | 3.3200%           |
| 2026-04-07 | 3.3200%           |
| 2026-04-08 | 3.3200%           |
| 2026-04-09 | 3.3100%           |
| 2026-04-10 | 3.3000%           |
| 2026-04-13 | 3.3000%           |
| 2026-04-14 | 3.3000%           |
| 2026-04-15 | 3.3100%           |
| 2026-04-16 | 3.3100%           |
| 2026-04-17 | 3.3300%           |
| 2026-04-20 | 3.3300%           |
| 2026-04-21 | 3.3300%           |
| 2026-04-22 | 3.3200%           |
| 2026-04-23 | 3.3200%           |
| 2026-04-24 | 3.3300%           |
| 2026-04-27 | 3.3300%           |
| 2026-04-28 | 3.3300%           |
| 2026-04-29 | 3.3300%           |
| 2026-04-30 | 3.3300%           |

**Beneficial/Record Owner Categories**
| Category      | Other Category   | Record Owner %   | Beneficial Owner %   |
|:---|:---|:---|:---|
| Broker-dealer |  | 99.9400%         | 0.0000%              |

## Part C: Schedule of Portfolio Securities

### Security 1: State Street U.S. Government Money Market Portfolio

- **C.1 - Title:** State Street U.S. Government Money Market Portfolio
- **C.6 - Investment Category:** Investment Company
- **Identifiers:** C.3 - CUSIP: FSSgAK1AV, C.3 - LEI: 549300EG2J8MKJKUK458, C.5 - Other ID: FSSgAK1AV
- **C.18 - Value (incl. sponsor support):** $185384735.17
- **C.18.a - Value (excl. sponsor support):** $185384735.17
- **C.19 - Percentage of Net Assets:** 100.0000%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2026-05-01
- **C.12 - Maturity Date (WAL):** 2026-05-01
- **C.13 - Final Legal Maturity Date:** 2026-05-01
- **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:** 2026-05-07

**By:** /s/ Chad Hallett

**Name of Signing Officer:** Chad Hallett

**Title of Signing Officer:** Deputy Treasurer