Form 4 for ATRA Atara Biotherapeutics, Inc.
Accepted 2026-03-19 00:00:00 ET · period of report 2026-03-17 · accession 0001193125-26-116060 · SEC index · Original document
Summary rows
Aggregated the way they appear in lists: one row per insider, transaction code and security table.
| X | Filed | Traded | Ticker | Insider | Title | Type | Price | Qty | Owned | ΔOwn | Value |
|---|---|---|---|---|---|---|---|---|---|---|---|
| DI | 2026-03-19 | 2026-03-17 | ATRA | Panacea Innovation Ltd | 10% | M - OptEx | $0.00 | +259.2K | 307.9K | +532% | $0 |
| DI | 2026-03-19 | 2026-03-17 | ATRA | Panacea Innovation Ltd | 10% | F - Tax | $5.23 | -5 | 307.9K | -0.0% | -$26.15 |
| DI | 2026-03-19 | 2026-03-17 | ATRA | Panacea Innovation Ltd | 10% | M - OptEx | $6.61 | -259.2K | 0 | -100% | -$1.71M |
Purchase Sale Sale after option exercise All abbreviations
Every reported transaction
| # | Table | Security | Date | Code | A/D | Shares | Price | Owned after | Own | Exercise / expiry | Underlying | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Common | Common Stock | 2026-03-17 | M | A | 259,163 | $0.00 | 307,899 | I See Footnotes | — | — | (F1) Represents securities held by Panacea Opportunity Fund I, L.P. (F2) James Huang is the sole owner of Panacea Innovation Limited, which is the sole owner of Panacea Venture Healthcare Fund II GP Company, Ltd. ("Fund II GP") and Panacea Opportunity Fund I GP Company, Ltd. ("Opportunity Fund GP"), which are the general partners of Panacea Venture Healthcare Fund II, L.P. and Panacea Opportunity Fund I, L.P. As a result, each of the Reporting Persons may be deemed to share beneficial ownership of the securities held of record by Panacea Venture Healthcare Fund II, L.P. and Panacea Opportunity Fund I, L.P., but each disclaims such beneficial ownership. |
| 2 | Common | Common Stock | 2026-03-17 | F | D | 5 | $5.23 | 307,894 | I See Footnotes | — | — | (F1) Represents securities held by Panacea Opportunity Fund I, L.P. (F2) James Huang is the sole owner of Panacea Innovation Limited, which is the sole owner of Panacea Venture Healthcare Fund II GP Company, Ltd. ("Fund II GP") and Panacea Opportunity Fund I GP Company, Ltd. ("Opportunity Fund GP"), which are the general partners of Panacea Venture Healthcare Fund II, L.P. and Panacea Opportunity Fund I, L.P. As a result, each of the Reporting Persons may be deemed to share beneficial ownership of the securities held of record by Panacea Venture Healthcare Fund II, L.P. and Panacea Opportunity Fund I, L.P., but each disclaims such beneficial ownership. |
| 3 | Derivative | Warrants | 2026-03-17 | M | D | 259,163 | $6.61 | 0 | I See Footnotes | $0.00 · — to — | 259,163 Common Stock | (F1) Represents securities held by Panacea Opportunity Fund I, L.P. (F2) James Huang is the sole owner of Panacea Innovation Limited, which is the sole owner of Panacea Venture Healthcare Fund II GP Company, Ltd. ("Fund II GP") and Panacea Opportunity Fund I GP Company, Ltd. ("Opportunity Fund GP"), which are the general partners of Panacea Venture Healthcare Fund II, L.P. and Panacea Opportunity Fund I, L.P. As a result, each of the Reporting Persons may be deemed to share beneficial ownership of the securities held of record by Panacea Venture Healthcare Fund II, L.P. and Panacea Opportunity Fund I, L.P., but each disclaims such beneficial ownership. (F4) The warrants are immediately exercisable and do not expire. Pursuant to the terms of the warrants, no portion of the warrants held by a holder may be exercised to the extent that, after giving effect to the attempted exercise, such holder, together with such holder's affiliates and any other person whose beneficial ownership of the Issuer's common stock would be aggregated with such holder's for the purposes of Section 13(d) of the Exchange Act, would beneficially own in excess of 19.99% of the outstanding common stock. |