ATRA Atara Biotherapeutics, Inc.

NASDAQ
$9.46

Atara Biotherapeutics, Inc. (ATRA) Institutional Ownership

What the institutions did with ATRA last quarter, from their 13F filings. Counting managers rather than shares is the point: a single index fund adding to a position tells you far less than four hundred separate managers all deciding to. Positions as reported for the quarter ended June 30, 2026.

Managers reporting
37
filed a 13F this quarter
Managers holding
36
+3 on the quarter
Buyers
16
4 opened new
Sellers
9
1 sold out entirely
Buyer share
64.0%
of managers who traded it
Breadth
+28.0
net buyers, as a share of those trading

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Largest holders

Manager Shares % of reported
EcoR1 Capital, LLC 1.6M 34.7%
ADAGE CAPITAL PARTNERS GP, L.L.C. 850.0K 19.0%
Point72 Asset Management, L.P. 687.7K 15.4%
Redmile Group, LLC 441.7K 9.9%
VANGUARD CAPITAL MANAGEMENT LLC 247.0K 5.5%
MACKENZIE FINANCIAL CORP 233.2K 5.2%
BlackRock, Inc. 84.5K 1.9%
GEODE CAPITAL MANAGEMENT, LLC 75.1K 1.7%
STALEY CAPITAL ADVISERS INC 50.0K 1.1%
VANGUARD FIDUCIARY TRUST CO 43.0K 1.0%
ACADIAN ASSET MANAGEMENT LLC 38.8K 0.9%
JANE STREET GROUP, LLC 30.3K 0.7%
STATE STREET CORP 26.5K 0.6%
NORTHERN TRUST CORP 16.6K 0.4%
FMR LLC 16.2K 0.4%
XTX Topco Ltd 15.3K 0.3%
BRIDGEWAY CAPITAL MANAGEMENT, LLC 14.0K 0.3%
MILLENNIUM MANAGEMENT LLC 12.7K 0.3%
CITADEL ADVISORS LLC 10.2K 0.2%
MORGAN STANLEY 9.2K 0.2%
ROYAL BANK OF CANADA 4.7K 0.1%
UBS Group AG 4.0K 0.1%
Vanguard Global Advisers, LLC 1.5K 0.0%
SBI Securities Co., Ltd. 1.4K 0.0%
JONES FINANCIAL COMPANIES LLLP 803 0.0%

Largest changes

Manager Action Previous Current Change
EcoR1 Capital, LLC Increased 99.6K 1.6M +1.5M
Point72 Asset Management, L.P. Increased 194.3K 687.7K +493.5K
ADAGE CAPITAL PARTNERS GP, L.L.C. Increased 700.0K 850.0K +150.0K
ACADIAN ASSET MANAGEMENT LLC Reduced 130.9K 38.8K -92.1K
MACKENZIE FINANCIAL CORP Reduced 313.6K 233.2K -80.4K
UBS Group AG Reduced 50.1K 4.0K -46.1K
MILLENNIUM MANAGEMENT LLC Reduced 47.7K 12.7K -35.0K
VANGUARD CAPITAL MANAGEMENT LLC Increased 217.9K 247.0K +29.2K
BRIDGEWAY CAPITAL MANAGEMENT, LLC Reduced 32.7K 14.0K -18.7K
XTX Topco Ltd New 0 15.3K +15.3K
CITADEL ADVISORS LLC New 0 10.2K +10.2K
VANGUARD FIDUCIARY TRUST CO Increased 33.6K 43.0K +9.4K
GEODE CAPITAL MANAGEMENT, LLC Increased 66.1K 75.1K +9.0K
BlackRock, Inc. Increased 79.0K 84.5K +5.4K
NORTHERN TRUST CORP Increased 12.3K 16.6K +4.3K
JANE STREET GROUP, LLC Reduced 33.9K 30.3K -3.5K
ROYAL BANK OF CANADA Increased 4.3K 4.7K +424
Caitong International Asset Management Co., Ltd New 0 311 +311
BARCLAYS PLC New 0 304 +304
RHUMBLINE ADVISERS Sold Out 175 0 -175
SBI Securities Co., Ltd. Reduced 1.6K 1.4K -170
JONES FINANCIAL COMPANIES LLLP Increased 703 803 +100
CITIGROUP INC Increased 1 97 +96
BNP PARIBAS FINANCIAL MARKETS Reduced 58 46 -12
MORGAN STANLEY Increased 9.2K 9.2K +9

13F filings are due 45 days after quarter end and cover long positions in U.S.-listed equities only, so this is a lagged and partial picture: shorts, bonds and foreign listings never appear. Options positions are excluded here rather than folded into the share counts. Political ownership is coming.