# DAY ONE BIOPHARMACEUTICALS I Equity Put

DAY ONE BIOPHARMACEUTICALS I Equity Put is a security (CUSIP 23954D959) tracked across SEC portfolio filings. 6 institutional managers reported $28.2M on Form 13F as of 2026-03-31.

## Summary

- Issuer: DAY ONE BIOPHARMACEUTICALS I
- Class: Equity Put
- CUSIP: 23954D959
- 13F holders: 6
- 13F value: $28.2M
- 13F period: 2026-03-31
- N-PORT fund positions: 0

## Top institutional holders (Form 13F)

| Manager | Location | Value | Shares |
| --- | --- | --- | --- |
| [WATER ISLAND CAPITAL LLC](https://search.stillhousedata.com/firm/113358) | New York, NY | $18.0M | — |
| [GROUP ONE TRADING, L.P.](https://search.stillhousedata.com/firm/37484) | CHICAGO, IL | $4.3M | — |
| JPMORGAN CHASE & CO | NEW YORK, NY | $4.1M | — |
| [SIMPLEX TRADING, LLC](https://search.stillhousedata.com/firm/153585) | CHICAGO, IL | $1.9M | — |
| [HRT FINANCIAL LP](https://search.stillhousedata.com/firm/152144) | NEW YORK, NY | $364 | 17,000 |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | BIRMINGHAM, AL | — | — |

## More

- [This page as markdown (for LLM agents)](https://search.stillhousedata.com/security/23954D959.md)
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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.