Atara Biotherapeutics, Inc. - Common Stock, par value $0.0001 per share (ATRA)

CUSIP: 046513107

Q3 2025 13F Holders as of 30 Sep 2025

Security identity
Security type / class
Equity / Common Stock, par value $0.0001 per share
Shares outstanding
9,606,000
Holder snapshot
Total 13F shares
15
Share change
+15
Total reported value
$215
Reported price per share
$14.33
Number of holders
1
Value change
+$215
Number of buys
1

Security key

046513107

Report period

Q3 2025

Institutions

1

Top holders

1

ATRA full security history Ownership snapshot Full 13F holder table Newer quarter: Q4 2025 Previous quarter: Q1 2025 Atara Biotherapeutics, Inc. SEC filings Atara Biotherapeutics, Inc. company facts

Broader feeds

Latest 13F filings Latest 13D/G filings Investors directory

Ownership snapshot

Top reported holders of ATRA - Atara Biotherapeutics, Inc. - Common Stock, par value $0.0001 per share (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.

Lead holder
Adiumentum Capital Fund I LP
13D/G signal
Adiumentum Capital Fund I LP
Evidence rows
15
Latest as of
30 Sep 2025
3/4/5 13D/G 13F Lead comparable stake: 20% 13D/G row: Adiumentum Capital Fund I LP Showing 1-6 of 15 holder rows.
Holder Evidence Ownership % Position 12M Net Δ As of
Adiumentum Capital Fund I LP
3/4/5 13D/G
Director, Other*, 10%+ Owner
3/4/5 13D/G
20%
from 13D/G
$10,487,308
1,586,588 shares
mixed-class rows
 — 16 May 2025
EcoR1 Capital, LLC
13D/G 13F
Company
13D/G 13F
9.9%
$10,258,030
715,853 shares
 $0 30 Sep 2025
Redmile Group, LLC
13F 3/4/5
Company · Director
13F 3/4/5
5.4%
from 3/4/5
$3,409,932
441,701 shares
 — 30 Jun 2025
Pascal Touchon
3/4/5
Director
3/4/5
0.95%
$589,339
77,955 shares
 — 10 Jun 2025
Carol Giltner Gallagher
3/4/5
Director
3/4/5
0.4%
$249,570
33,012 shares
 — 10 Jun 2025
William K. Heiden
3/4/5
Director
3/4/5
0.27%
$167,741
22,188 shares
 — 10 Jun 2025
How to read this table

Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.

13F holder rows

Institutional holders as of Q3 2025

Investor-level positions for this CUSIP, loaded as an interactive table.

Institutions
1
Shares
15
Rows available
1
Investor Option Weight % Change % Reported value * Price Shares Share Change Activity Report Period

* Reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that failed the local validity check.

Compare Q3 2025 vs Q1 2025 Across Filers

Q1 2025 holders
0
Q3 2025 holders
1
Holder diff
1
Investor Q1 2025 Shares Q3 2025 Shares Share Diff Share Chg % Q1 2025 value Q3 2025 value Value change Value Chg %

Trend: ostatnie 8 kwartałów (+ wybrane okresy porównania).

Quarterly Holders Trend
Quarterly Value Trend
Quarterly Shares Trend
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