TANANBAUM JAMES B. purchased 25.0% of their position (507.87K shares) of ALUMIS INC. on the open market
Open‑market purchase worth $3.09M — a significant purchase. The strongest form of insider conviction signal.
P · 4 purchases
Filed: 11/19/2025ACC: 0001104659-25-114266
+507.87K
Net shares
Net buyer
$3.09M
Total acquired
4
Open market trades
4B · 0S
4
Total transactions
507.87K acquired
Non-Derivative Transactions4
Common Stock
Indirect
Shares
+50K
Price / share
$5.60
Trade value
$280K
% of position
2.5%
11/17/2025
2.03M→2.08M
Common Stock
Indirect
Shares
+150K
Price / share
$5.59
Trade value
$838.50K
% of position
7.2%
11/17/2025
2.08M→2.23M
Common Stock
Indirect
Shares
+117.37K
Price / share
$6.19
Trade value
$726.55K
% of position
5.3%
11/18/2025
2.23M→2.35M
Common Stock
Indirect
Shares
+190.50K
Price / share
$6.56
Trade value
$1.25M
% of position
8.1%
11/19/2025
2.35M→2.54M
Total
Net shares
+507.87K
Net value
$3.09M
| Security | Date | Type | Shares | Price / Share | Trade Value | % of Position | Held Before | Held After |
|---|---|---|---|---|---|---|---|---|
| Common Stock Indirect | 11/17/2025 | P · Purchase | +50K | $5.60 | $280K | 2.5% | 2.03M | 2.08M |
| Common Stock Indirect | 11/17/2025 | P · Purchase | +150K | $5.59 | $838.50K | 7.2% | 2.08M | 2.23M |
| Common Stock Indirect | 11/18/2025 | P · Purchase | +117.37K | $6.19 | $726.55K | 5.3% | 2.23M | 2.35M |
| Common Stock Indirect | 11/19/2025 | P · Purchase | +190.50K | $6.56 | $1.25M | 8.1% | 2.35M | 2.54M |
| Total | +507.87K | $3.09M | ||||||
Derivative Transactions0
No derivative transactions reported
Non-Derivative Holdings (Post-Transaction)5
Common Stock
IndirectShares owned1.18M
Common Stock
IndirectShares owned194.46K
Common Stock
IndirectShares owned4.25M
Common Stock
IndirectShares owned1.96M
Common Stock
IndirectShares owned5.58M
Total
13.16M indirect13.16M
| Security Title | Shares Owned | Ownership Type |
|---|---|---|
| Common Stock | 1.18M | Indirect |
| Common Stock | 194.46K | Indirect |
| Common Stock | 4.25M | Indirect |
| Common Stock | 1.96M | Indirect |
| Common Stock | 5.58M | Indirect |
| Total | 13.16M | 13.16M indirect |
Derivative Holdings (Post-Transaction)0
No derivative holdings reported