Companies / Day One Biopharmaceuticals, Inc.
Day One Biopharmaceuticals, Inc.
DAWNCIK 1845337BRISBANE, CA
Financials · FY2025
Ownership
103.3M shares outstanding · as of Apr 15, 2026
Ownership
| Insiders | 0.57% | 589,322 |
| 10%+ / strategic | 10.97% | 11,332,398 |
| Institutions | 86.65% | 89,537,646 |
| Public float | 1.81% | 1,874,803 |
% of common shares outstanding (exact, from the latest cover-page filing). Institutions are quarterly 13F snapshots; insiders reflect current officers & directors.
Insiders 9
View all →| Insider | % of shares | Shares |
|---|---|---|
York Charles N IICOO and CFO | 0.30% | 312,025 |
Bender JeremyCEOCHIEF EXECUTIVE OFFICER · Director | 0.20% | 204,603 |
Dubow AdamGen Counsel & Secretary | 0.07% | 72,694 |
Merendino LaurenFormerChief Commercial Officer | 0.06% | 60,157 |
Vasconcelles MichaelFormerHead of Research and Dev. | <0.01% | 4,397 |
AI Day1 LLC10% owner | 0.00% | 0 |
Access Industries Holdings LLC10% owner | — | — |
Access Industries Management, LLC10% owner | — | — |
Blavatnik Len10% owner | — | — |
Institutional holders 207
View all →| Holder | Value | % of shares |
|---|---|---|
| $82.37M | 8.55% | |
| $79.82M | 3.60% | |
| $59.77M | 6.21% | |
| $58.55M | 6.08% | |
| $56.29M | 2.54% | |
| $53.28M | 5.53% | |
| $52.79M | 2.38% | |
| $48.46M | 5.03% | |
| $41.92M | 1.89% | |
| $41.33M | 1.87% |
Activity
Mar 31, 2026View all →
InsidersInstitutions
Who's accumulating and trimming this stock (13F).| Date | Actor | Action | Security | Value | Shares Δ | Position after | Impact |
|---|---|---|---|---|---|---|---|
| Q2 2026 as of | BlackRock, Inc. 13F manager | Exit | Common stock | $-82.37M | -8.8M -100.00% | 0 | high |
| Q1 2026 as of | AQR Arbitrage LLC 13F manager | New | Common stock | $52.79M | +2.5M | 2,462,154 2.38% of shares | high |
| Q2 2026 as of | State Street Corporation 13F manager | Exit | Common stock | $-39.98M | -4.3M -100.00% | 0 | medium |
| Q1 2026 as of | Perceptive Advisors LLC 13F manager | New | Common stock | $37.64M | +1.8M | 1,755,799 1.70% of shares | medium |
| Q1 2026 as of | Soros Fund Management LLC 13F manager | New | Common stock | $33.00M | +1.5M | 1,539,100 1.49% of shares | medium |
| Q1 2026 as of | Balyasny Asset Management L.P. 13F manager | Add | Common stock | $24.34M | +1.1M +76.20% | 2,625,235 2.54% of shares | medium |
| Q1 2026 as of | Hudson Bay Capital Management LP 13F manager | Trim | Common stock | $-22.08M | -1.0M -60.59% | 670,000 0.65% of shares | medium |
| Q1 2026 as of | Water Island Capital LLC 13F manager | New | Common stock | $20.24M | +944K | 944,247 0.91% of shares | medium |
5%+ ownership events
Schedule 13D / 13G
| Filer | Stance | % of class |
|---|---|---|
| Vanguard Group Inc | Passive13G/A | — |
| Glazer Capital, LLC | Passive13G | — |
| Fmr LLC | Passive13G/A | — |
| Vestal Point Capital, LP | Passive13G | — |
Securities
via CUSIP / OpenFIGI
| Symbol | Type | CUSIP |
|---|---|---|
| DAWN | — | 23954D109 |