PHATHOM PHARMACEUTICALS INC (PHAT) Institutional Ownership Changes & 13F Activity
PHATHOM PHARMACEUTICALS INC (PHAT). Institutional ownership data tracks hedge funds, asset managers, and other institutional investors based on recent SEC Form 13F filings (Q4 2025). This page analyzes institutional buying and selling activity, new holdings, and sold-out positions in the latest reporting period. Notable filers include Millennium Management Llc, Nea Management Company, Llc, 683 Capital Management, Llc, Catalio Capital Management, Lp, and Divisadero Street Capital Management, Lp.
| Institution | Type | Change in shares | Change Position % | Shares | Reported stock balance | Portfolio quarter | Filing date |
|---|---|---|---|---|---|---|---|
| Catalio Capital Management, Lp | Buy | +698,996 | — | 698,996 | $11.60M | Q4 2025 | Sep 02, 2026 |
| Ensign Peak Advisors, Inc | Sell | -151,324 | -6.0% | 2,352,020 | $39.02M | Q4 2025 | Aug 18, 2026 |
| Kera Capital Partners, Inc. | Buy | +24,255 | — | 24,255 | $331.57K | Q4 2025 | Feb 23, 2026 |
| Virtu Financial Llc | Buy | +15,540 | — | 15,540 | $258.00K | Q4 2025 | Feb 23, 2026 |
| Newedge Advisors, Llc | Buy | +200,823 | — | 200,823 | $3.16M | Q4 2025 | Feb 18, 2026 |
| Raymond James Financial Inc | Buy | +24,390 | — | 24,390 | $404.63K | Q4 2025 | Feb 18, 2026 |
| Millennium Management Llc | Buy | +2,082,180 | — | 2,082,180 | $34.54M | Q4 2025 | Feb 17, 2026 |
| Nea Management Company, Llc | Buy | +1,960,169 | — | 1,960,169 | $32.52M | Q4 2025 | Feb 17, 2026 |
| 683 Capital Management, Llc | Buy | +1,785,000 | — | 1,785,000 | $29.61M | Q4 2025 | Feb 17, 2026 |
| Divisadero Street Capital Management, Lp | Buy | +662,312 | — | 662,312 | $10.99M | Q4 2025 | Feb 17, 2026 |
| Moore Capital Management, Lp | Buy | +600,000 | — | 600,000 | $9.95M | Q4 2025 | Feb 17, 2026 |
| Susquehanna International Group, Llp | Buy | +549,171 | — | 549,171 | $9.11M | Q4 2025 | Feb 17, 2026 |
| Summittx Capital, L.P. | Buy | +517,820 | — | 517,820 | $8.59M | Q4 2025 | Feb 17, 2026 |
| Stepstone Group Lp | Buy | +422,085 | — | 422,085 | $4.97M | Q4 2025 | Feb 17, 2026 |
| Northern Trust Corp | Buy | +356,466 | — | 356,466 | $5.91M | Q4 2025 | Feb 17, 2026 |
| Citadel Advisors Llc | Buy | +311,315 | — | 311,315 | $5.16M | Q4 2025 | Feb 17, 2026 |
| Brevan Howard Capital Management Lp | Buy | +276,989 | — | 276,989 | $4.60M | Q4 2025 | Feb 17, 2026 |
| Susquehanna Portfolio Strategies, Llc | Buy | +267,962 | — | 267,962 | $4.45M | Q4 2025 | Feb 17, 2026 |
| D. E. Shaw & Co., Inc. | Buy | +261,068 | — | 261,068 | $4.33M | Q4 2025 | Feb 17, 2026 |
| Bank Of America Corp | Buy | +258,996 | — | 258,996 | $4.30M | Q4 2025 | Feb 17, 2026 |
| Balyasny Asset Management L.P. | Buy | +207,085 | — | 207,085 | $3.44M | Q4 2025 | Feb 17, 2026 |
| Woodline Partners Lp | Buy | +187,291 | — | 187,291 | $3.11M | Q4 2025 | Feb 17, 2026 |
| Ameriprise Financial Inc | Buy | +185,744 | — | 185,744 | $3.08M | Q4 2025 | Feb 17, 2026 |
| Gilder Gagnon Howe & Co Llc | Buy | +145,174 | — | 145,174 | $2.41M | Q4 2025 | Feb 17, 2026 |
| Trexquant Investment Lp | Buy | +136,824 | — | 136,824 | $2.27M | Q4 2025 | Feb 17, 2026 |
| Wellington Management Group Llp | Buy | +134,546 | — | 134,546 | $2.23M | Q4 2025 | Feb 17, 2026 |
| Varcov Co. | Buy | +86,759 | — | 86,759 | $1.44M | Q4 2025 | Feb 17, 2026 |
| Creative Planning | Buy | +80,766 | — | 80,766 | $1.34M | Q4 2025 | Feb 17, 2026 |
| Dark Forest Capital Management Lp | Buy | +62,248 | — | 62,248 | $1.03M | Q4 2025 | Feb 17, 2026 |
| Two Sigma Investments, Lp | Buy | +57,783 | — | 57,783 | $958.62K | Q4 2025 | Feb 17, 2026 |
Frequently asked questions about PHAT activity
Which institutional owners are buying PHAT?
Institutional owners buying PHAT include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.
What does "buy" mean in PHAT activity?
"Buy" means an investor increased their reported position in PHAT compared to the prior reporting period. This reflects growing exposure to PHATHOM PHARMACEUTICALS INC (PHAT) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).
Is institutional interest in PHAT increasing?
Institutional interest in PHAT can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.
Related PHAT Institutional Insights
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