# MFS Institutional Money Market Portfolio MFS Institutional Money Market Portfolio, Class A

MFS Institutional Money Market Portfolio MFS Institutional Money Market Portfolio, Class A is a security (CUSIP 55291X109) tracked across SEC portfolio filings. 32 registered fund positions totaling $1.9B via N-PORT as of 2026-05-31.

## Summary

- Issuer: MFS Institutional Money Market Portfolio
- Class: MFS Institutional Money Market Portfolio, Class A
- CUSIP: 55291X109
- Asset category: STIV
- 13F holders: 0
- N-PORT fund positions: 32
- N-PORT value: $1.9B
- N-PORT report: 2026-05-31

## Top fund holders (N-PORT)

_Showing 15 of 32 fund positions by value._

| Fund | Registrant | Value | % of fund |
| --- | --- | --- | --- |
| [MFS International Equity Fund](https://search.stillhousedata.com/fund/S000002537) | MFS Series Trust XVII | $521.1M | 181.54% |
| [MFS Growth Fund](https://search.stillhousedata.com/fund/S000002419) | MFS Series Trust II | $417.6M | 100.27% |
| [MFS Mid Cap Value Fund](https://search.stillhousedata.com/fund/S000002499) | MFS SERIES TRUST XI | $222.5M | 139.13% |
| [MFS International New Discovery Fund](https://search.stillhousedata.com/fund/S000002437) | MFS Series Trust V | $175.9M | 241.42% |
| [MFS Income Fund](https://search.stillhousedata.com/fund/S000002491) | MFS Series Trust VIII | $150.2M | 183.19% |
| [MFS Limited Maturity Fund](https://search.stillhousedata.com/fund/S000002495) | MFS Series Trust IX | $94.4M | 282.50% |
| [MFS High Income Fund](https://search.stillhousedata.com/fund/S000002427) | MFS Series Trust III | $60.3M | 308.03% |
| [MFS Massachusetts Investors Growth Stock Fund](https://search.stillhousedata.com/fund/S000000695) | MFS Massachusetts Investors Growth Stock Fund | $57.1M | 61.84% |
| [MFS Conservative Allocation Fund](https://search.stillhousedata.com/fund/S000002510) | MFS SERIES TRUST X | $34.9M | 96.89% |
| [Massachusetts Investors Trust](https://search.stillhousedata.com/fund/S000000696) | MASSACHUSETTS INVESTORS TRUST | $33.8M | 53.60% |
| MFS INTERMEDIATE INCOME TRUST | MFS INTERMEDIATE INCOME TRUST | $13.2M | 437.96% |
| MFS MUNICIPAL INCOME TRUST | MFS MUNICIPAL INCOME TRUST | $12.1M | 489.73% |
| MFS HIGH INCOME MUNICIPAL TRUST | MFS HIGH INCOME MUNICIPAL TRUST | $9.5M | 738.60% |
| MFS CHARTER INCOME TRUST | MFS CHARTER INCOME TRUST | $7.6M | 280.36% |
| [MFS Global Alternative Strategy Fund](https://search.stillhousedata.com/fund/S000019515) | MFS Series Trust XV | $7.6M | 349.70% |

## More

- [This page as markdown (for LLM agents)](https://search.stillhousedata.com/security/55291X109.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.