# EDGAR Filing Document

**Accession Number:** 0000939934
**File Stem:** 0001104659-25-123277
**Filing Date:** 2025-12
**Character Count:** 2699
**Document Hash:** 210c5f215a80cd6d2c41e3a598fffd69
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-123277.hdr.sgml**: 20251219

**ACCESSION NUMBER**: 0001104659-25-123277

**CONFORMED SUBMISSION TYPE**: 497

**PUBLIC DOCUMENT COUNT**: 4

**FILED AS OF DATE**: 20251219

**DATE AS OF CHANGE**: 20251219

**EFFECTIVENESS DATE**: 20251219

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** SEI INSTITUTIONAL INVESTMENTS TRUST
- **CENTRAL INDEX KEY:** 0000939934

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 0531

**FILING VALUES:**
- **FORM TYPE:** 497
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 033-58041
- **FILM NUMBER:** 251588472

**BUSINESS ADDRESS:**
- **STREET 1:** 1 FREEDOM VALLEY DRIVE
- **CITY:** OAK
- **STATE:** PA
- **ZIP:** 19456
- **BUSINESS PHONE:** 610 676-3097

**MAIL ADDRESS:**
- **STREET 1:** 1 FREEDOM VALLEY DRIVE
- **CITY:** OAK
- **STATE:** PA
- **ZIP:** 19456

## Series and Classes Contracts Data

### SIIT WORLD EQUITY EX-US FUND (Series ID: S000006765)

---

|  |  |  |
|:---|:---|:---|
| Class Name                             | Ticker Symbol | Class ID   |
| SIIT WORLD EQUITY EX-US FUND - CLASS A | WEUSX         | C000018354 |

---

## Series and Classes Contracts Data

### SIIT WORLD EQUITY EX-US FUND (Series ID: S000006765)

| Class ID   | Class Name                             | Ticker Symbol   |
|:---|:---|:---|
| C000018354 | SIIT WORLD EQUITY EX-US FUND - CLASS A | WEUSX           |

SEI INSTITUTIONAL INVESTMENTS TRUST

World Equity Ex-US Fund<br>(the "Fund")

Supplement Dated December 19, 2025<br>to the Prospectus (the "Prospectus"), dated September 30, 2025, as amended November 3, 2025 and <br>November 18, 2025 and the Statement of Additional Information (the "SAI"), dated September 30, 2025, <br>as amended November 3, 2025, November 18, 2025 and December 18, 2025

This Supplement provides new and additional information beyond that contained in the Prospectus and SAI and should be read in conjunction with such Prospectus and SAI.

*The Prospectus and SAI are hereby amended and supplemented to reflect the following changes to the Fund.*

<u>Change in Portfolio Management of the Fund</u>

*Nomura Investments Fund Advisers, a series of Nomura Investment Management Business Trust (f/k/a Delaware Investments Fund Advisers, a series of Macquarie Investment Management Business Trust) no longer serves as a sub-adviser to the Fund. As such, all references to Nomura Investments Fund Advisers, a series of Nomura Investment Management Business Trust are hereby deleted from the Prospectus and SAI.*

*There are no other changes to the Prospectus or SAI*

PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE

SEI-F-1633 (12/25)

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