# ALLEGRO MICROSYSTEMS INC COM

ALLEGRO MICROSYSTEMS INC COM is a security (CUSIP 01749D105) tracked across SEC portfolio filings. 361 institutional managers reported $4.2B on Form 13F as of 2026-06-30; 38 registered fund positions totaling $992.2M via N-PORT as of 2026-05-31.

## Summary

- Issuer: ALLEGRO MICROSYSTEMS INC
- Class: COM
- CUSIP: 01749D105
- Asset category: EC
- 13F holders: 361
- 13F value: $4.2B
- 13F period: 2026-06-30
- N-PORT fund positions: 38
- N-PORT value: $992.2M
- N-PORT report: 2026-05-31

## Top institutional holders (Form 13F)

_Showing 15 of 361 managers by value._

| Manager | Location | Value | Shares |
| --- | --- | --- | --- |
| FMR LLC | BOSTON, MA | $864.6M | 27,421,206 |
| BlackRock, Inc. | New York, NY | $394.0M | 12,494,868 |
| Capital Research Global Investors | Los Angeles, CA | $392.1M | 12,435,558 |
| [VANGUARD GROUP INC](https://search.stillhousedata.com/firm/105958) | Valley Forge, PA | $374.7M | 14,202,528 |
| JPMORGAN CHASE & CO | NEW YORK, NY | $242.6M | 8,652,068 |
| STATE STREET CORP | BOSTON, MA | $164.8M | 5,228,104 |
| PRINCIPAL FINANCIAL GROUP INC | DES MOINES, IA | $103.7M | 1,489,791 |
| [MASSACHUSETTS FINANCIAL SERVICES CO /MA/](https://search.stillhousedata.com/firm/110045) | Boston, MA | $100.5M | 1,443,495 |
| [Clearbridge Investments, LLC](https://search.stillhousedata.com/firm/137028) | New York, NY | $90.3M | 2,863,710 |
| [GEODE CAPITAL MANAGEMENT, LLC](https://search.stillhousedata.com/firm/115504) | BOSTON, MA | $77.5M | 2,456,820 |
| MORGAN STANLEY | NEW YORK, NY | $71.7M | 2,275,285 |
| DIMENSIONAL FUND ADVISORS LP | AUSTIN, TX | $68.4M | 2,170,487 |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. | PHILADELPHIA, PA | $65.6M | 2,080,641 |
| LOOMIS SAYLES & CO L P | BOSTON, MA | $52.8M | 1,674,108 |
| Bank of New York Mellon Corp | NEW YORK, NY | $49.9M | 716,952 |

## Top fund holders (N-PORT)

_Showing 15 of 38 fund positions by value._

| Fund | Registrant | Value | % of fund |
| --- | --- | --- | --- |
| [Capital World Growth & Income Fund](https://search.stillhousedata.com/fund/S000009001) | Capital World Growth & Income Fund | $283.7M | 17.77% |
| [Invesco Small Cap Value Fund](https://search.stillhousedata.com/fund/S000027837) | AIM Sector Funds (Invesco Sector Funds) | $215.3M | 200.23% |
| [SMALLCAP World Fund Inc](https://search.stillhousedata.com/fund/S000009599) | SMALLCAP World Fund Inc | $178.2M | 21.98% |
| State Street SPDR S&P MidCap 400SM ETF Trust | SPDR S&P MIDCAP 400 ETF TRUST | $118.0M | 48.73% |
| [VANGUARD EXPLORER FUND](https://search.stillhousedata.com/fund/S000002578) | VANGUARD EXPLORER FUND | $62.3M | 28.60% |
| [VANGUARD EXTENDED MARKET INDEX FUND](https://search.stillhousedata.com/fund/S000002841) | VANGUARD INDEX FUNDS | $43.6M | 5.36% |
| [Fidelity Growth Company Fund](https://search.stillhousedata.com/fund/S000007119) | Fidelity Mt. Vernon Street Trust | $26.8M | 2.72% |
| [LORD ABBETT DEVELOPING GROWTH FUND INC](https://search.stillhousedata.com/fund/S000006834) | LORD ABBETT DEVELOPING GROWTH FUND, INC. | $18.5M | 83.44% |
| [Fidelity Advisor Stock Selector Mid Cap Fund](https://search.stillhousedata.com/fund/S000005114) | Fidelity Advisor Series I | $12.4M | 48.85% |
| [T. Rowe Price Small-Cap Value Fund, Inc.](https://search.stillhousedata.com/fund/S000002121) | T. ROWE PRICE SMALL-CAP VALUE FUND, INC. | $6.5M | 7.06% |
| [Optimum Small-Mid Cap Growth Fund](https://search.stillhousedata.com/fund/S000002424) | Optimum Fund Trust | $4.7M | 62.40% |
| [Columbia Mid Cap Index Fund](https://search.stillhousedata.com/fund/S000010826) | COLUMBIA FUNDS SERIES TRUST | $4.2M | 16.70% |
| [TAX MANAGED SMALL CAP PORTFOLIO](https://search.stillhousedata.com/fund/S000005252) | Tax-Managed Small-Cap Portfolio | $3.6M | 195.13% |
| [U.S. MICRO CAP PORTFOLIO](https://search.stillhousedata.com/fund/S000000948) | DFA INVESTMENT DIMENSIONS GROUP INC | $3.2M | 4.31% |
| [VOYA SMALLCAP OPPORTUNITIES PORTFOLIO](https://search.stillhousedata.com/fund/S000008640) | Voya Variable Products Trust | $2.8M | 164.96% |

## More

- [This page as markdown (for LLM agents)](https://search.stillhousedata.com/security/01749D105.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.