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Atara Biotherapeutics

36 hedge funds and large institutions have $51.3M invested in Atara Biotherapeutics in 2026 Q2 according to their latest regulatory filings, with 4 funds opening new positions, 12 increasing their positions, 8 reducing their positions, and 1 closing their positions.

New
Increased
Maintained
Reduced
Closed

323% more capital invested

Capital invested by funds: $12.1M → $51.3M (+$39.2M)

300% more first-time investments, than exits

New positions opened: 4 | Existing positions closed: 1

50% more repeat investments, than reductions

Existing positions increased: 12 | Existing positions reduced: 8

18.23% more ownership

Funds ownership: 31.36%49.59% (+18%)

9% more funds holding

Funds holding: 3336 (+3)

Holders
36
Holders Change
+3
Holders Change %
+9.09%
% of All Funds
0.43%
Holding in Top 10
Holding in Top 10 Change
Holding in Top 10 Change %
% of All Funds
New
4
Increased
12
Reduced
8
Closed
1
Calls
$2K
Puts
Net Calls
+$2K
Net Calls Change
+$1K

ATRA Hedge Fund Activity: Q2 2026 in Review

36 of the 8,279 institutional investors tracked by Wall St. Rank reported a position in Atara Biotherapeutics (ATRA) for Q2 2026, worth a combined $51.3M — up 323% from $12.1M a quarter earlier.

Buyers outnumbered sellers: 4 funds opened new ATRA positions and 1 closed out — a net gain of 3 holders — while 12 added to existing stakes and 8 trimmed.

The largest buyer was EcoR1 Capital, adding an estimated $11.6M. The largest seller was Acadian Asset Management, cutting an estimated $734K.

  • 36 institutional investors held Atara Biotherapeutics (ATRA) as of Q2 2026, up from 33 in Q1 2026.
  • Funds reported $51.3M of Atara Biotherapeutics stock for Q2 2026, up 323% quarter-over-quarter.
  • 4 funds opened new Atara Biotherapeutics positions in Q2 2026 and 1 closed out, a net change of +3 holders.
  • The largest Atara Biotherapeutics buyer in Q2 2026 was EcoR1 Capital, an estimated $11.6M added.
  • The largest Atara Biotherapeutics seller in Q2 2026 was Acadian Asset Management, an estimated $734K sold.

Based on aggregated 13F filings for Q2 2026.