PHATHOM PHARMACEUTICALS INC PHAT
COM · Common Stock · CUSIP 71722W107 · ISIN US71722W1071
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersFlorham Park, NJ
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($45.7k this quarter). Holder counts are more reliable. Shares outstanding: 79.8m as of 2026-04-27, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $11.11. Options: 6 managers hold calls ($14.6m notional), 3 hold puts ($713.3k).
Trends to Q1 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 94 |
| Q4 2022 | 87 |
| Q1 2023 | 85 |
| Q2 2023 | 104 |
| Q3 2023 | 111 |
| Q4 2023 | 118 |
| Q1 2024 | 115 |
| Q2 2024 | 115 |
| Q3 2024 | 134 |
| Q4 2024 | 145 |
| Q1 2025 | 138 |
| Q2 2025 | 118 |
| Q3 2025 | 133 |
| Q4 2025 | 173 |
| Q1 2026 | 174 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q2 2024 | 64 | 37 |
| Q3 2024 | 83 | 28 |
| Q4 2024 | 87 | 49 |
| Q1 2025 | 72 | 63 |
| Q2 2025 | 59 | 74 |
| Q3 2025 | 72 | 39 |
| Q4 2025 | 94 | 60 |
| Q1 2026 | 106 | 75 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2025 | $15.4m | $12.1m | 0.79 |
| Q3 2025 | $14.3m | $345.9k | 0.02 |
| Q4 2025 | $17.8m | $854.4k | 0.05 |
| Q1 2026 | $14.6m | $713.3k | 0.05 |
Biggest buyers
| MILLENNIUM MANAGEMENT LLC | Added | +1.9m |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. | New | +1.2m |
| FRANKLIN RESOURCES INC | New | +994.5k |
| PERCEPTIVE ADVISORS LLC | New | +925.0k |
| MARSHALL WACE, LLP | New | +860.7k |
| EcoR1 Capital, LLC | New | +625.0k |
| BlackRock, Inc. | Added | +506.4k |
| SummitTX Capital, L.P. | Added | +478.1k |
| TWO SIGMA INVESTMENTS, LP | Added | +424.4k |
| Invesco Ltd. | Added | +401.6k |
Biggest sellers
| Ensign Peak Advisors, Inc | Reduced | -724.2k |
| Divisadero Street Capital Management, LP | Sold out | -662.3k |
| MOORE CAPITAL MANAGEMENT, LP | Sold out | -600.0k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | -456.2k |
| Catalio Capital Management, LP | Reduced | -451.2k |
| NEXT CENTURY GROWTH INVESTORS LLC | Sold out | -393.8k |
| JANE STREET GROUP, LLC | Sold out | -384.8k |
| Brevan Howard Capital Management LP | Reduced | -182.4k |
| CAXTON ASSOCIATES LLP | Sold out | -182.0k |
| D. E. Shaw & Co., Inc. | Reduced | -128.6k |
Biggest calls
| CITADEL ADVISORS LLC | Added | $5.7m515.9k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $3.6m323.8k shares |
| GROUP ONE TRADING LLC | Added | $1.8m162.3k shares |
| SIG BROKERAGE, LP | New | $1.3m120.0k shares |
| SIMPLEX TRADING, LLC | Reduced | $1.2m106.2k shares |
| JANE STREET GROUP, LLC | Added | $979.9k88.2k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $458.8k41.3k shares |
| CITADEL ADVISORS LLC | Reduced | $213.3k19.2k shares |
| SIMPLEX TRADING, LLC | Added | $41.1k3.7k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
Frazier Life Sciences Public Fund, L.P.
13D · may seek influence
no change · filed 2025-11-04
Stated purposeItem 4 is hereby amended to remove references to "FLSPOF" and the "FLSPOF Shares" from the first paragraph. Full filing |
8.6% |
| BlackRock, Inc. 13G · institution +0.9 pts · filed 2026-07-29 | 5.5% |
Fell to 5% or below in the last year: MILLENNIUM MANAGEMENT LLC (4.2%, 2026-07-20)
Insider purchases and sales in Q1 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q2 2024 | 0 | — | 1 | $38.1k | — |
| Q3 2024 | 0 | — | 3 | $575.1k | — |
| Q4 2024 | 2 | $180.3k | 2 | $19.3k | — |
| Q1 2025 | 1 | $44.2k | 3 | $221.3k | — |
| Q2 2025 | 2 | $216.9k | 1 | $16.7k | — |
| Q3 2025 | 0 | — | 1 | $19.7k | — |
| Q4 2025 | 0 | — | 1 | $7.1k | — |
| Q1 2026 | 0 | — | 0 | — | — |
None reported in Q1 2026.
Holders, Q1 2026
| Manager | Shares | Change |
|---|---|---|
| Frazier Life Sciences Management, L.P. 3.56% of their portfolio | 12.5m $138.5m | Unchanged |
| Medicxi Ventures Management (Jersey) Ltd 8.45% of their portfolio | 7.5m $82.9m | Unchanged |
| Invesco Ltd. 0.00% of their portfolio | 4.3m $48.0m | Added +401.6k |
| BlackRock, Inc. 0.00% of their portfolio | 4.1m $45.1m | Added +506.4k |
| MILLENNIUM MANAGEMENT LLC 0.03% of their portfolio | 4.0m $44.7m | Added +1.9m |
| Carlyle Group Inc. 0.37% of their portfolio | 3.5m $38.8m | Unchanged |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 2.6m $28.7m | First filing |
| NEA Management Company, LLC 1.24% of their portfolio | 2.0m $21.8m | Unchanged |
| 683 Capital Management, LLC 1.91% of their portfolio | 1.9m $20.6m | Added +65.0k |
| Ensign Peak Advisors, Inc 0.03% of their portfolio | 1.6m $18.1m | Reduced -724.2k |
| Catalys Pacific, LLC 7.19% of their portfolio | 1.5m $16.6m | Added +64.8k |
| GW&K Investment Management, LLC 0.14% of their portfolio | 1.4m $15.8m | Added +114.4k |
| STATE STREET CORP 0.00% of their portfolio | 1.4m $15.4m | Added +237.4k |
| WASATCH ADVISORS LP 0.10% of their portfolio | 1.3m $14.9m | Added +9.2k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 1.3m $14.8m | Added +254.6k |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. 0.02% of their portfolio | 1.2m $13.4m | New |
| SummitTX Capital, L.P. 0.35% of their portfolio | 995.9k $11.1m | Added +478.1k |
| FRANKLIN RESOURCES INC 0.00% of their portfolio | 994.5k $11.0m | New |
| PERCEPTIVE ADVISORS LLC 0.20% of their portfolio | 925.0k $10.3m | New |
| MARSHALL WACE, LLP 0.01% of their portfolio | 860.7k $9.6m | New |
| Propel Bio Management, LLC 5.90% of their portfolio | 841.3k $9.4m | Added +100.4k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 666.0k $7.4m | First filing |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 626.2k $7.0m | Added +234.2k |
| EcoR1 Capital, LLC 0.30% of their portfolio | 625.0k $6.9m | New |
| Avidity Partners Management LP 0.59% of their portfolio | 498.8k $5.6m | Added +292.7k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 482.1k $5.4m | Added +424.4k |
| StepStone Group LP 2.26% of their portfolio | 422.1k $4.7m | Unchanged |
| NORTHERN TRUST CORP 0.00% of their portfolio | 415.0k $4.6m | Added +58.5k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 409.0k $4.5m | Added +11.1k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 383.1k $4.3m | Added +71.7k |
| Woodline Partners LP 0.02% of their portfolio | 369.1k $4.1m | Added +181.8k |
| UBS Group AG 0.00% of their portfolio | 360.4k $4.0m | Added +56.0k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 338.7k $3.8m | First filing |
| RENAISSANCE TECHNOLOGIES LLC 0.01% of their portfolio | 305.8k $3.4m | New |
| Trexquant Investment LP 0.02% of their portfolio | 293.3k $3.3m | Added +156.5k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 287.4k $3.0m | Reduced -9.3k |
| Squarepoint Ops LLC 0.01% of their portfolio | 275.2k $3.1m | New |
| Susquehanna Portfolio Strategies, LLC 0.04% of their portfolio | 268.0k $3.0m | Unchanged |
| Simplify Asset Management Inc. 0.04% of their portfolio | 262.4k $2.9m | Reduced -59.5k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 254.2k $2.8m | Added +68.5k |
| Catalio Capital Management, LP 0.58% of their portfolio | 247.8k $2.8m | Reduced -451.2k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 208.1k $2.3m | Reduced -50.9k |
| Birchview Capital, LP 1.23% of their portfolio | 195.0k $2.2m | Unchanged |
| NewEdge Advisors, LLC 0.01% of their portfolio | 183.0k $2.0m | Reduced -17.8k |
| XTX Topco Ltd 0.03% of their portfolio | 160.5k $1.8m | Added +121.1k |
| Hennion & Walsh Asset Management, Inc. 0.05% of their portfolio | 145.9k $1.6m | Added +31.0k |
| GILDER GAGNON HOWE & CO LLC 0.02% of their portfolio | 139.9k $1.6m | Reduced -5.3k |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 132.5k $1.5m | Reduced -128.6k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 124.0k $1.4m | Added +1.1k |
| Nuveen, LLC 0.00% of their portfolio | 117.3k $1.3m | Added +8.5k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 111.8k $1.2m | Reduced -22.8k |
| Stratos Wealth Partners, LTD. 0.01% of their portfolio | 100.0k $1.1m | Added +49.7k |
| GSA CAPITAL PARTNERS LLP 0.07% of their portfolio | 97.1k $1.1m | Added +14.4k |
| Balyasny Asset Management L.P. 0.00% of their portfolio | 95.3k $1.1m | Reduced -111.8k |
| Brevan Howard Capital Management LP 0.01% of their portfolio | 94.6k $1.1m | Reduced -182.4k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 93.0k $1.0m | Reduced -456.2k |
| Swiss National Bank 0.00% of their portfolio | 92.6k $1.0m | Added +8.6k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 85.7k $951.9k | Added +79.0k |
| Freestone Grove Partners LP 0.01% of their portfolio | 84.6k $939.6k | New |
| HUSSMAN STRATEGIC ADVISORS, INC. 0.20% of their portfolio | 84.0k $933.2k | Reduced -63.0k |
| KBC Group NV 0.00% of their portfolio | 77.1k $857.0k | New |
| MORGAN STANLEY 0.00% of their portfolio | 76.7k $851.9k | Reduced -41.1k |
| Burkehill Global Management, LP 0.04% of their portfolio | 75.0k $833.2k | New |
| Engineers Gate Manager LP 0.01% of their portfolio | 73.8k $820.5k | Added +29.6k |
| Creative Planning 0.00% of their portfolio | 70.2k $779.8k | Reduced -10.6k |
| Penn Mutual Asset Management 3.57% of their portfolio | 62.8k $697.7k | Unchanged |
| Campbell & CO Investment Adviser LLC 0.04% of their portfolio | 62.0k $689.1k | Reduced -53.3k |
| Virtus Investment Advisers, LLC 0.18% of their portfolio | 58.0k $644.2k | Added +11.0k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 55.8k $619.8k | Added +25.2k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 55.5k $616.2k | Added +1.0k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 55.4k $615.9k | Added +3.3k |
| DIADEMA PARTNERS LP 0.25% of their portfolio | 54.6k $607.2k | New |
| STIFEL FINANCIAL CORP 0.00% of their portfolio | 54.0k $600.4k | Added +2.4k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 52.5k $583.0k | Added +15.4k |
| Stonepine Capital Management, LLC 0.49% of their portfolio | 50.0k $555.6k | New |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 49.4k $819.4k | Unchanged |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 46.1k $512.3k | Reduced -21.9k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 44.0k $488.9k | Added +28.7k |
| ADAR1 Capital Management, LLC 0.03% of their portfolio | 42.9k $476.6k | Unchanged |
| Aquatic Capital Management LLC 0.01% of their portfolio | 40.9k $453.9k | New |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 40.2k $446.9k | Added +79 |
| ALGERT GLOBAL LLC 0.01% of their portfolio | 39.4k $438.0k | New |
| VARCOV Co. 0.16% of their portfolio | 39.2k $435.2k | Reduced -47.6k |
| TUDOR INVESTMENT CORP ET AL 0.00% of their portfolio | 38.2k $424.7k | Added +9.7k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 36.5k $405.1k | Added +3.1k |
| TOCQUEVILLE ASSET MANAGEMENT L.P. 0.01% of their portfolio | 35.2k $391.1k | Added +500 |
| ALLSTATE CORP 0.00% of their portfolio | 32.7k $363.2k | New |
| COMMONWEALTH EQUITY SERVICES, LLC 0.00% of their portfolio | 32.2k $358.1k | Added +1.3k |
| Legal & General Group Plc 0.00% of their portfolio | 32.0k $355.9k | Reduced -2.2k |
| Man Group plc 0.00% of their portfolio | 30.4k $337.2k | New |
| CITIGROUP INC 0.00% of their portfolio | 29.4k $326.3k | Added +910 |
| VANGUARD ASSET MANAGEMENT, Ltd 0.00% of their portfolio | 28.5k $316.7k | First filing |
| Kera Capital Partners, Inc. 0.04% of their portfolio | 26.8k $298.0k | Added +2.6k |
| Persistent Asset Partners Ltd 0.12% of their portfolio | 26.8k $297.4k | Added +13.8k |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 26.5k $294.5k | First filing |
| Jump Financial, LLC 0.00% of their portfolio | 26.4k $293.8k | Added +9.0k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 26.3k $292.5k | Added +1.9k |
| MetLife Investment Management, LLC 0.00% of their portfolio | 25.8k $287.1k | Unchanged |
| BARCLAYS PLC 0.00% of their portfolio | 25.4k $281.7k | Reduced -59.5k |
| Zurcher Kantonalbank (Zurich Cantonalbank) 0.00% of their portfolio | 25.0k $277.7k | Added +5.1k |