SPTX Institutional Ownership & Shareholders
Seaport Therapeutics, Inc. (SPTX) is currently held by 55 institutional investors tracked by InsiderSet, with a combined reported market value of approximately $769.12M based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026.
Arch Venture Management, Llc is currently the largest disclosed institutional shareholder of SPTX tracked by InsiderSet, reporting ownership valued at approximately $136.60M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $125.96M, representing an estimated loss of -7.79% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 77% of the total disclosed SPTX value among the investors covered in this analysis. Major shareholders include Arch Venture Management, Llc, General Atlantic, L.P., Sofinnova Investments, Inc., and several other long-term asset managers with concentrated positions in Seaport Therapeutics, Inc. (SPTX).
This page ranks the largest institutional SPTX shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
55
Total Reported Value
$769.12M
Largest Holder
Arch Venture Management, Llc
Largest Position
$136.60M
Insider Transactions (90d)
0
Latest Filing Quarter
Q2 2026
New Institutional Positions
55
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Arch Venture Management, Llc | 12.42% | 6,294,951 | $136,600,437 | $125,961,970 | -$10,638,467 | -7.79% | |
| General Atlantic, L.P. | 4.56% | 6,101,582 | $132,526,361 | $122,092,656 | -$10,433,705 | -7.87% | |
| Sofinnova Investments, Inc. | 4.14% | 3,564,871 | $77,428,998 | $71,333,069 | -$6,095,929 | -7.87% | |
| Goldman Sachs Group Inc | 0.00% | 2,178,642 | $47,320,104 | $43,594,626 | -$3,725,478 | -7.87% | |
| Canada Pension Plan Investment Board | 0.02% | 1,975,791 | $42,914,181 | $39,535,578 | -$3,378,603 | -7.87% | |
| Jpmorgan Chase & Co | 0.00% | 1,815,845 | $40,892,829 | $36,335,058 | -$4,557,771 | -11.15% | |
| Foresite Capital Management Vi Llc | 6.02% | 1,779,521 | $38,651,196 | $35,608,215 | -$3,042,981 | -7.87% | |
| Price T Rowe Associates Inc | 0.00% | 1,308,604 | $28,424,000 | $26,185,166 | -$2,238,834 | -7.88% | |
| Fmr Llc | 0.00% | 1,185,100 | $25,740,372 | $23,713,851 | -$2,026,521 | -7.87% | |
| Bellevue Group Ag | 0.50% | 1,100,000 | $23,892,000 | $22,011,000 | -$1,881,000 | -7.87% | |
| Siren, L.L.C. | 0.48% | 1,095,316 | $23,790,264 | $21,917,273 | -$1,872,991 | -7.87% | |
| Jennison Associates Llc | 0.01% | 1,079,669 | $23,450,411 | $21,604,177 | -$1,846,234 | -7.87% | |
| Ra Capital Management, L.P. | 0.13% | 700,000 | $15,204,000 | $14,007,000 | -$1,197,000 | -7.87% | |
| Vanguard Capital Management Llc | 0.00% | 599,217 | $13,014,993 | $11,990,332 | -$1,024,661 | -7.87% | |
| Woodline Partners Lp | 0.04% | 586,345 | $12,735,413 | $11,732,763 | -$1,002,650 | -7.87% | |
| Braidwell Lp | 0.40% | 500,000 | $10,860,000 | $10,005,000 | -$855,000 | -7.87% | |
| Perceptive Advisors Llc | 0.17% | 500,000 | $10,860,000 | $10,005,000 | -$855,000 | -7.87% | |
| Principal Financial Group Inc | 0.00% | 377,391 | $7,611,976 | $7,551,594 | -$60,382 | -0.79% | |
| Aberdeen Group Plc | 0.01% | 310,355 | $6,740,911 | $6,210,204 | -$530,707 | -7.87% | |
| Ubs Group Ag | 0.00% | 279,184 | $6,063,876 | $5,586,472 | -$477,404 | -7.87% | |
| Blackrock, Inc. | 0.00% | 229,863 | $4,992,624 | $4,599,559 | -$393,065 | -7.87% | |
| Seven Grand Managers, Llc | 0.20% | 225,000 | $4,887,000 | $4,502,250 | -$384,750 | -7.87% | |
| Citadel Advisors Llc | 0.00% | 191,144 | $4,151,648 | $3,824,791 | -$326,857 | -7.87% | |
| Geode Capital Management, Llc | 0.00% | 175,866 | $3,821,843 | $3,519,079 | -$302,764 | -7.92% | |
| Pier Capital, Llc | 0.49% | 169,985 | $3,692,074 | $3,401,400 | -$290,674 | -7.87% | |
| Ameriprise Financial Inc | 0.00% | 131,788 | $2,862,435 | $2,637,078 | -$225,357 | -7.87% | |
| Charles Schwab Investment Management Inc | 0.00% | 97,693 | $2,121,892 | $1,954,837 | -$167,055 | -7.87% | |
| Vanguard Fiduciary Trust Co | 0.00% | 87,772 | $1,906,408 | $1,756,318 | -$150,090 | -7.87% | |
| Pentwater Capital Management Lp | 0.01% | 83,000 | $1,802,760 | $1,660,830 | -$141,930 | -7.87% | |
| Manufacturers Life Insurance Company, The | 0.00% | 82,565 | $1,793,312 | $1,652,126 | -$141,186 | -7.87% | |
| Alyeska Investment Group, L.P. | 0.00% | 75,000 | $1,629,000 | $1,500,750 | -$128,250 | -7.87% | |
| State Street Corp | 0.00% | 66,650 | $1,447,638 | $1,333,667 | -$113,972 | -7.87% | |
| Alps Advisors Inc | 0.01% | 70,921 | $1,430,477 | $1,419,129 | -$11,348 | -0.79% | |
| Td Asset Management Inc | 0.00% | 47,944 | $1,041,344 | $959,359 | -$81,985 | -7.87% | |
| Millennium Management Llc | 0.00% | 45,337 | $984,720 | $907,193 | -$77,527 | -7.87% | |
| Gsa Capital Partners Llp | 0.05% | 33,178 | $721,000 | $663,892 | -$57,108 | -7.92% | |
| Dafna Capital Management Llc | 0.13% | 32,400 | $703,728 | $648,324 | -$55,404 | -7.87% | |
| Northern Trust Corp | 0.00% | 31,802 | $690,739 | $636,358 | -$54,381 | -7.87% | |
| Adar1 Capital Management, Llc | 0.03% | 26,000 | $564,720 | $520,260 | -$44,460 | -7.87% | |
| Burkehill Global Management, Lp | 0.02% | 25,000 | $543,000 | $500,250 | -$42,750 | -7.87% | |
| Ghisallo Capital Management Llc | 0.01% | 25,000 | $543,000 | $500,250 | -$42,750 | -7.87% | |
| Squarepoint Ops Llc | 0.00% | 24,753 | $537,635 | $495,308 | -$42,327 | -7.87% | |
| Morgan Stanley | 0.00% | 11,692 | $253,951 | $233,957 | -$19,994 | -7.87% | |
| Xtx Topco Ltd | 0.00% | 10,983 | $238,551 | $219,770 | -$18,781 | -7.87% | |
| Weiss Asset Management Lp | 0.00% | 10,000 | $217,200 | $200,100 | -$17,100 | -7.87% | |
| Zimmer Partners, Lp | 0.01% | 10,000 | $217,200 | $200,100 | -$17,100 | -7.87% | |
| Vanguard Portfolio Management Llc | 0.00% | 9,081 | $197,239 | $181,711 | -$15,528 | -7.87% | |
| Vanguard Global Advisers, Llc | 0.00% | 7,159 | $155,493 | $143,252 | -$12,241 | -7.87% | |
| Strs Ohio | 0.00% | 3,800 | $76,646 | $76,038 | -$608 | -0.79% | |
| Citigroup Inc | 0.00% | 2,454 | $53,301 | $49,105 | -$4,196 | -7.87% |
Frequently asked questions about SPTX
Who are the largest institutional holders of SPTX?
The largest institutional holders of SPTX reported in the latest SEC Form 13F filings include Arch Venture Management, Llc, General Atlantic, L.P., Sofinnova Investments, Inc., Goldman Sachs Group Inc, and Canada Pension Plan Investment Board. InsiderSet ranks institutional holders by their latest reported SPTX position.
What is SPTX institutional ownership?
This page tracks SPTX positions reported by institutional investment managers through SEC Form 13F. Seaport Therapeutics, Inc. (SPTX) institutional ownership on InsiderSet reflects disclosed 13F holdings among the managers we analyze, not every shareholder of the stock.
How many institutions own SPTX?
InsiderSet currently tracks 55 institutional managers reporting SPTX holdings in the latest available 13F data. This count reflects institutions included in the SEC Form 13F filings analyzed by InsiderSet and should not be interpreted as the total number of SPTX shareholders.
How much SPTX stock do institutions own?
Institutional investment managers disclosed approximately $769.12M in SPTX holdings for Q2 2026. This figure is reported 13F value as of the filing period, not necessarily today's market value.
When was SPTX institutional ownership last updated?
The latest SPTX institutional ownership data on InsiderSet is based on SEC Form 13F filings for the quarter ended June 30, 2026. Form 13F filings are generally reported after the quarter ends, so the holdings shown represent the latest publicly disclosed positions rather than real-time institutional holdings.
Are institutional SPTX holdings real-time?
No. Form 13F data is not real-time. It represents positions reported by institutional investment managers as of the end of the reporting quarter. An institution may have changed its SPTX position after the reporting date.
Are institutions buying or selling SPTX?
Institutional buying and selling can be analyzed by comparing SPTX positions across consecutive 13F reporting periods. InsiderSet's SPTX Ownership Changes page shows institutions that increased, reduced, initiated, or exited positions based on reported 13F holdings. View SPTX ownership changes.
How has SPTX institutional ownership changed over time?
InsiderSet tracks SPTX institutional holdings across multiple 13F reporting periods, allowing investors to compare institutional holder counts, reported value, and reported shares over time.