SPTX Seaport Therapeutics (SPTX) Insider Trading, Ownership & Congress Trades

Pharma & Biotech · Pharmaceutical preparations · CIK 0002042347

Quote by TradingView

Activist 13D

House members buying, 1 year

STOCK Act, US House only, disclosed up to 45 days after the trade

Funds added, last quarter

13F, latest reported quarter

Conversions, 180 days

Codes C/M, not in net · no price filed

What the filings say about SPTX

Insiders, 180 days

+$20.0M net bought

2 buyers

Activist stakes (13D), 180 days

2 filings

Largest: 11.9% of the class

Seaport Therapeutics insider trades (Form 4)

Form 4 buys and sells (codes P and S). Grants, option exercises and conversions excluded.

Over the last 180 days, Seaport Therapeutics, Inc. insiders bought a net $20.0M of stock across 2 Form 4 purchases and sales, with 2 insiders buying. Source: SEC Form 4 filings, as of 2026-10-27.

Insider

Filed

Value

Since filing

HOMBACH ROBERT J.

Director

BUY

2026-06-24 SECtraded 2026-06-22

13,000

$235.8K

+6.5%

Context

First Form 4 purchase or sale (code P or S) here by this insider on our record.
The trade is 100.0% of the 13,000 shares held after it.
No other insider bought within 30 days.
55 funds added in the 13F quarter to Jun 30, 2026.

Insider activity: Director HOMBACH ROBERT J. bought about $235.8K of SPTX on Jun 22, 2026; 55 funds added in the latest 13F quarter.

ARCH Venture Partners XII, L.P.

BUY

2026-05-04 SEC

1,100,000

$19.8M

+28.8%

Context

First Form 4 purchase or sale (code P or S) here by this insider on our record.
The trade is 17.5% of the 6,294,951 shares held after it.
No other insider bought within 30 days.
55 funds added in the 13F quarter to Jun 30, 2026.

Insider activity: Insider ARCH Venture Partners XII, L.P. bought about $19.8M of SPTX on May 4, 2026, the largest insider purchase at the company on our record; 55 funds added in the latest 13F quarter.

2 transactions on record · a thin record, read with care

Since filing: total return from the first close after the filing to the latest close, dividend-adjusted. Not a forecast.

Context lines are counts over the filings above and returns from our own price history, never a price level. Not investment advice.

See all insider buying · insider selling

Seven facts, ranked against the sector · Rank is not a forecast

Insiders

net +$20.0M over 180 days

+$19.8M of it by a 10%+ holder

more than 97% of Pharma & Biotech

Congress

no House purchase disclosed in the last 12 months

Funds

55 funds bought in last quarter

below 51% of Pharma & Biotech

Revenue

no revenue reported in any filing

Margin

no margin: no revenue reported

Buybacks

no share repurchases reported

Short interest

19.8% of the float short (float per yahoo 2026-10-26) · 8.9 days to cover · settled 2026-09-30

more than 60% of Pharma & Biotech

The situation: each line is one rule over one dataset

General Atlantic, L.P. disclosed a 5%+ stake (11.5%) in the last six months.

What changed in the last 30 days

Nothing new filed in the last 30 days

Watch SPTX

A free account keeps a watchlist and can send one email a day when insiders, funds or Congress file on the names in it. No password and no card.

The year, with the filings on it

Total return over 12 months. Each marker is a filing; hover or tap one for the detail.

+3.9%12M

Insider buy13D/G stake

Indexed to 100, dividend-adjusted, not a price chart. When a name files heavily, the largest trades are drawn first.

Who owns SPTX: institutional holders (13F)

13F holdings, latest reported quarter

ARCH Venture Management, LLC

6,294,951 sh

$136.6M

GENERAL ATLANTIC, L.P.

6,101,582 sh

$132.5M

Sofinnova Investments, Inc.

3,564,871 sh

$77.4M

GOLDMAN SACHS GROUP INC

2,178,642 sh

$47.3M

TRV GP VI, LLC

2,061,222 sh

$44.8M

Congress trades in SPTX

No Congress trades reported

No House member has disclosed a trade in this stock. See what Congress is buying.

Activist and 5% holders (13D/13G)

13D: intends to influence · 13G: passive

General Atlantic, L.P.

Activist 13D · 2026-05-11

11.5%

General Atlantic (SPV) GP, LLC

Activist 13D · 2026-05-11

11.5%

General Atlantic Partners 100, L.P.

Activist 13D · 2026-05-11

11.5%

General Atlantic (SP), L.P.

Activist 13D · 2026-05-11

11.5%

General Atlantic Partners (Lux) SCSp

Activist 13D · 2026-05-11

11.5%

SPTX planned insider sales (Form 144)

No planned-sale notices

No insider has filed to sell. Watch this after a run-up.

SPTX mutual fund holders (N-PORT)

Funds ranked by the share of their own portfolio in this stock (N-PORT).

JPMorgan Small Cap Growth Fund

$18.3M position · as of 2026-06-30

0.7%

PGIM Jennison Health Sciences Fund

$8.0M position · as of 2026-05-29

0.6%

Dunham Small Cap Growth Fund

$355.4K position · as of 2026-07-31

0.4%

JPMorgan Small Cap Blend Fund

$5.9M position · as of 2026-06-30

0.3%

EQ/T.Rowe Price Health Sciences Portfolio

$321.8K position · as of 2026-06-30

0.2%

Health Sciences Trust

$456.7K position · as of 2026-06-30

0.2%

SEC N-PORT, monthly, about 60 days late · funds ≥ $10M · % is the share of the fund's own portfolio

Clinical pipeline

2 registered trials, 2 still running (ClinicalTrials.gov). A status change is dated here weeks before the press release.

Phase 2

2 active

Matched by sponsor name. Trials run under a subsidiary's own name are not included.

Live price

Daily candles from TradingView, under their licence. No filings marked.

Show the live price chart

Why this name is on the desk

An activist crossed the 5% line with declared intent.

The record shows a net $20.0M bought by insiders over 180 days, 55 funds added last quarter. Each figure is a federal filing, dated the day it went public.

Backtest this pattern Open the screener

Same sector, ranked by filing activity

Sector by SEC SIC code

UTHR CPIX MRNA REGN LLY ALNY MDGL CITR DNA VRTX NUVL TWST

SPTX Stock Sonar score 3/7 axes

Find similar shapes Compare

SPTX ranks highest on insider conviction (89th percentile) and institutional and government (49th), and lowest on risk and compliance (15th), among Pharma & Biotech peers.

Insider conviction

Inputs

Net Form 4 buying (codes P and S), 180d$20.0M · 97 pct, sector of 428
Insider buyers, 180d2 · 81 pct, sector of 437

Institutional and government

Inputs

Funds adding, latest quarter55 · 49 pct, sector of 698
Congress net buyers, 365dno Congress trades in 365 days
Federal contracts, 180dno federal contracts in 180 days
Lobbying spend, 4 quartersno lobbying filings in the last four quarters

Risk and compliance

Inputs

Short interest, % of float+19.8% · 15 pct, sector of 813
Recalls per $1B revenue, 3yrevenue under $50M or not filed, so a count cannot be scaled to size
EPA cases per $1B revenue, 5yrevenue under $50M or not filed, so a count cannot be scaled to size
New text in Risk Factors, latest 10-Kneeds two 10-Ks with a Risk Factors section (not 20-F filers or stubs)

4 not measured: Profitability, Financial health, Growth, US patents

Profitability needs 2 of 4 inputs, 0 present: fewer than four consecutive quarters of net income; fewer than four consecutive quarters of operating income
Financial health needs 1 of 2 inputs, 0 present: no debt line filed
Growth needs 1 of 2 inputs, 0 present: no backlog line filed, or no year-earlier backlog; no revenue for this year and the year before
US patents needs 1 of 2 inputs, 0 present: patent data not loaded yet

3 of 7 axes scored. Each is a percentile against sector peers (all companies when the sector is thin); higher is better. An unscored axis is unmeasured, not low. How it is scored

SPTX filings, in plain words

Are Seaport Therapeutics insiders buying or selling SPTX?

In the 180 days to 2026-10-27, Seaport Therapeutics insiders were net buyers, a net $20.0M across purchases and sales reported on Form 4, by 2 buyers.

Read the full summary

In the 180 days to 2026-10-27, Seaport Therapeutics insiders were net buyers of SPTX, a net $20.0M across purchases and sales reported on Form 4 by 2 buyers. Most of that figure, $19.8M, came from a holder of 10% or more rather than an officer or director. 2 activist Schedule 13D filings in the last 180 days declared an intent to influence the company, the largest for 11.9% of the class. Each figure is counted from SEC and House filings as of 2026-10-27, dated the day the filing was made public.

Explore insider trading and ownership data

Every company we track, ranked by each kind of filing

Insider buying Insider selling Congress stock trades Activist 13D stakes Form 144 planned sales CEO pay vs performance All companies