ARCH VENTURE PARTNERS XII, LLC purchased 21.2% of their position (1.10M shares) of SEAPORT THERAPEUTICS, INC. on the open market
Open‑market purchase worth $19.80M — a significant purchase. The strongest form of insider conviction signal.
P · 1 purchase
Filed: 5/4/2026ACC: 0001193125-26-204458
10% Owner
Since Apr 2026
+1.10M
Net shares
Net buyer
$19.80M
Total acquired
1
Open market trades
1B · 0S
5
Total transactions
6.29M acquired · 5.19M disposed
Non-Derivative Transactions3
Common Stock
Indirect
Shares
+2.51M
Price / share
—
Trade value
—
% of position
New position
5/4/2026
0.00→2.51M
Common Stock
Indirect
Shares
+2.68M
Price / share
—
Trade value
—
% of position
106.7%
5/4/2026
2.51M→5.19M
Common Stock
Indirect
Shares
+1.10M
Price / share
$18.00
Trade value
$19.80M
% of position
21.2%
5/4/2026
5.19M→6.29M
Total
Net shares
+6.29M
Net value
$19.80M
| Security | Date | Type | Shares | Price / Share | Trade Value | % of Position | Held Before | Held After |
|---|---|---|---|---|---|---|---|---|
| Common Stock Indirect | 5/4/2026 | C · Conversion | +2.51M | — | — | New position | 0.00 | 2.51M |
| Common Stock Indirect | 5/4/2026 | C · Conversion | +2.68M | — | — | 106.7% | 2.51M | 5.19M |
| Common Stock Indirect | 5/4/2026 | P · Purchase | +1.10M | $18.00 | $19.80M | 21.2% | 5.19M | 6.29M |
| Total | +6.29M | $19.80M | ||||||
Derivative Transactions2
Series A-2 Preferred Stock
Indirect
Converts to
Common Stock
2.51M shares
Shares
−2.51M
Strike price
Held after
0.00
Exercisable
—
5/4/2026
Series B Preferred Stock
Indirect
Converts to
Common Stock
2.68M shares
Shares
−2.68M
Strike price
Held after
0.00
Exercisable
—
5/4/2026
| Security | Converts To | Date | Type | Shares | Strike Price | Exercisable | Held After |
|---|---|---|---|---|---|---|---|
| Series A-2 Preferred Stock Indirect | Common Stock2.51M shares | 5/4/2026 | C · Conversion | −2.51M | — | 0.00 | |
| Series B Preferred Stock Indirect | Common Stock2.68M shares | 5/4/2026 | C · Conversion | −2.68M | — | 0.00 |