| Insider | Role | Shares | Value | Buys | Sells |
|---|---|---|---|---|---|
| Date | Ticker | Insider | Role | Type | Shares | Price | Value | Chg% | SEC |
|---|---|---|---|---|---|---|---|---|---|
| Insider | Role | Shares | Value | Buys | Sells |
|---|---|---|---|---|---|
| Date | Ticker | Insider | Role | Type | Shares | Price | Value | Chg% | SEC |
|---|---|---|---|---|---|---|---|---|---|
Director, 10% Owner | Director
4 companies
James B. Tananbaum is Director, 10% Owner at LTGO, with reported holdings spanning 4 companies. James B. Tananbaum's net worth is not public. Form 4 filings only show shares in the companies where this person is an insider; those holdings are worth an estimated $291.9M at current prices.
Our model assigns James B. Tananbaum a middling insider score of 59/100, based on 8 past trades. Over a 12-month horizon, 66.7% of those trades were profitable, with an average 12-month return of +41.4%.
James B. Tananbaum's largest disclosed position is in IRON as Director, worth about $237.7M.
James B. Tananbaum has 10 Form 4 filings on record from February 2021 to August 2026, across 4 companies: Director, 10% Owner at Latigo Biotherapeutics (LTGO), 2026; Director, 10% Owner at Alumis (ALMS), 2024–2026; Director, 10% Owner at Disc Medicine (IRON), 2021, and 1 more.
The 48 reported transactions were 23 conversions, 12 open-market purchases, 8 stock awards and 4 other transactions, plus smaller numbers of other types.
Counted by filing, the open-market trades come to 6 purchases worth about $53.3M and no sales.
The largest open-market purchase was 2,500,000 shares of ALMS at an average $16.00 on July 1, 2024, about $40.0M. Twelve months later ALMS was down 76%.
| Date | Ticker | Role | Type | Shares | Price | Value | Chg% | 3M | 12M | SEC |
|---|---|---|---|---|---|---|---|---|---|---|
| Aug 10, 2026 | LTGO Latigo Biotherapeutics, Inc. | Director, 10% Owner | Buy | 140,000 | $18.00 | $2,520,000.00 | +7.5% | - | - | |
| Jan 8, 2026 | ALMS Alumis Inc. | Director, 10% Owner | Buy | 411,764 | $17.00 | $6,999,988.00 | +16.5% | +24.9% | - | |
| Nov 21, 2025 | ALMS Alumis Inc. | Director, 10% Owner | Buy | 72,212 | $7.38 | $532,924.56 | +2.8% | +300.1% | - | |
| Nov 19, 2025 | ALMS Alumis Inc. | Director, 10% Owner | Buy | 507,874 | $6.09 | $3,094,725.06 | +25.0% | +304.6% | - | |
| May 6, 2025 | ALMS Alumis Inc. | Director, 10% Owner | Buy | 45,000 | $4.50 | $202,300.00 | +1.1% | -6.0% | +486.2% | |
| Jul 1, 2024 | ALMS Alumis Inc. | Director, 10% Owner | Buy | 2,500,000 | $16.00 | $40,000,000.00 | +146.8% | -14.8% | -75.9% |