# SPERO THERAPEUTICS INC COM

SPERO THERAPEUTICS INC COM is a security (CUSIP 84833T103) tracked across SEC portfolio filings. 53 institutional managers reported $48.1M on Form 13F as of 2026-06-30; 6 registered fund positions totaling $1.4M via N-PORT as of 2026-05-31.

## Summary

- Issuer: SPERO THERAPEUTICS INC
- Class: COM
- CUSIP: 84833T103
- Asset category: EC
- 13F holders: 53
- 13F value: $48.1M
- 13F period: 2026-06-30
- N-PORT fund positions: 6
- N-PORT value: $1.4M
- N-PORT report: 2026-05-31

## Top institutional holders (Form 13F)

_Showing 15 of 53 managers by value._

| Manager | Location | Value | Shares |
| --- | --- | --- | --- |
| GSK plc | London, X0 | $21.5M | 9,190,606 |
| Pfizer Inc | New York, NY | $5.5M | 2,362,348 |
| [VANGUARD GROUP INC](https://search.stillhousedata.com/firm/105958) | Valley Forge, PA | $4.9M | 2,083,462 |
| [RENAISSANCE TECHNOLOGIES LLC](https://search.stillhousedata.com/firm/106661) | NEW YORK, NY | $2.8M | 1,189,235 |
| Alphabet Inc. | Mountain View, CA | $2.1M | 889,979 |
| [TWO SIGMA INVESTMENTS, LP](https://search.stillhousedata.com/firm/137137) | New York, NY | $2.1M | 885,631 |
| [GEODE CAPITAL MANAGEMENT, LLC](https://search.stillhousedata.com/firm/115504) | BOSTON, MA | $1.2M | 519,922 |
| BlackRock, Inc. | New York, NY | $1.0M | 433,202 |
| [CITADEL ADVISORS LLC](https://search.stillhousedata.com/firm/148826) | MIAMI, FL | $996K | 376,458 |
| Anson Funds Management LP | DALLAS, TX | $987K | 421,956 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | BALA CYNWYD, PA | $893K | 333,115 |
| STATE STREET CORP | BOSTON, MA | $503K | 214,751 |
| [Ionic Capital Management LLC](https://search.stillhousedata.com/firm/156400) | NEW YORK, NY | $458K | 195,939 |
| [Squarepoint Ops LLC](https://search.stillhousedata.com/firm/172116) | New York, NY | $455K | 194,301 |
| JANE STREET GROUP, LLC | NEW YORK, NY | $427K | 106,345 |

## Top fund holders (N-PORT)

| Fund | Registrant | Value | % of fund |
| --- | --- | --- | --- |
| [VANGUARD EXTENDED MARKET INDEX FUND](https://search.stillhousedata.com/fund/S000002841) | VANGUARD INDEX FUNDS | $1.2M | 0.15% |
| [Invesco NASDAQ Future Gen 200 ETF](https://search.stillhousedata.com/fund/S000077288) | Invesco Exchange-Traded Fund Trust II | $101K | 53.28% |
| [VANGUARD BALANCED INDEX FUND](https://search.stillhousedata.com/fund/S000002560) | VANGUARD VALLEY FORGE FUNDS | $57K | 0.01% |
| [VANGUARD INSTITUTIONAL TOTAL STOCK MARKET INDEX FUND](https://search.stillhousedata.com/fund/S000002855) | VANGUARD INSTITUTIONAL INDEX FUNDS | $53K | 0.02% |
| [Blackstone Alternative Multi-Strategy Fund](https://search.stillhousedata.com/fund/S000045538) | Blackstone Alternative Investment Funds | $14K | 0.04% |
| Guggenheim Active Allocation Fund | Guggenheim Active Allocation Fund | $408 | 0.01% |

## More

- [This page as markdown (for LLM agents)](https://search.stillhousedata.com/security/84833T103.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.