# VANGUARD ULTRA-SHORT TREASURY ETF

VANGUARD ULTRA-SHORT TREASURY ETF is a ETF series of VANGUARD INSTITUTIONAL INDEX FUNDS (series S000090173). Net assets $898.4M as of 2026-03-31. Index fund.

## Profile

- Series ID: S000090173
- Registrant: VANGUARD INSTITUTIONAL INDEX FUNDS
- LEI: 529900IZR0IZYR5N4F48
- Net assets: $898.4M
- Total assets: $898.4M
- As of: 2026-03-31
- Type: ETF, Index

## Advisers

- [The Vanguard Group, Inc. (Advisor)](https://search.stillhousedata.com/firm/105958)

## Top holdings (92 reported)

_Showing 15 of 92 holdings by value._

| Holding | Ticker | Value | % of fund |
| --- | --- | --- | --- |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797SD0) | — | $34.0M | 377.98% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797SL2) | — | $33.5M | 372.46% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797QD2) | — | $29.1M | 323.44% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797QN0) | — | $28.9M | 321.48% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797SM0) | — | $22.8M | 253.60% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797SN8) | — | $22.6M | 251.71% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797TG2) | — | $22.4M | 248.92% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797TH0) | — | $22.2M | 246.99% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797TJ6) | — | $21.9M | 243.75% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797SW8) | — | $21.6M | 240.51% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797SV0) | — | $21.5M | 238.88% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797SP3) | — | $20.8M | 231.76% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797RF6) | — | $17.4M | 193.65% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797QX8) | — | $16.7M | 185.75% |
| [United States Treasury Bill](https://search.stillhousedata.com/security/912797RG4) | — | $15.8M | 175.73% |

## Net asset history

| Report date | Net assets |
| --- | --- |
| 2026-03-31 | $898.4M |
| 2025-12-31 | $530.1M |
| 2025-09-30 | $433.1M |
| 2025-06-30 | $247.3M |
| 2025-03-31 | $94.3M |

## More

- [Registrant: VANGUARD INSTITUTIONAL INDEX FUNDS](https://search.stillhousedata.com/registrant/862084)
- [This page as markdown (for LLM agents)](https://search.stillhousedata.com/fund/S000090173.md)
- [Search all SEC filings, advisers and people on Adviser Search](https://search.stillhousedata.com/)

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Source: public SEC filing data via Adviser Search (https://search.stillhousedata.com).
Agents: this data is also queryable via MCP tools and read-only SQL — see https://search.stillhousedata.com/llms.txt.