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ATRA · Atara Biotherapeutics, Inc.
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ATRA Atara Biotherapeutics (ATRA) Insider Trading, Ownership & Congress Trades

Pharma & Biotech · Biological products, (no diagnostic substances) · CIK 0001604464
Quote by TradingView
Form 144 · 1
House members buying, 1 year
0
STOCK Act, US House only, disclosed up to 45 days after the trade
Funds added, last quarter
15
13F, latest reported quarter
Conversions, 180 days
1
Codes C/M, not in net · no price filed

What the filings say about ATRA

Insiders, 180 days
+$2.5M net bought
2 buyers · 3 sellers · 0% of sales under a 10b5-1 plan
Planned sales (Form 144), 90 days
$42.3K
1 notice

Atara Biotherapeutics insider trades (Form 4)

Form 4 buys and sells (codes P and S). Grants, option exercises and conversions excluded.

Over the last 180 days, Atara Biotherapeutics, Inc. insiders bought a net $2.5M of stock across 138 Form 4 purchases and sales, with 2 insiders buying. Source: SEC Form 4 filings, as of 2026-10-28.

Insider
Filed
Shares
Value
Since filing
Cherry Brian N
Director
BUY
2026-09-04 SEC
104,166
$1.0M
-18.9%
Context
  • First Form 4 purchase or sale (code P or S) here by this insider on our record.
  • The trade is 62.6% of the 166,486 shares held after it.
  • No other insider bought within 30 days.
  • 15 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Director Cherry Brian N bought about $1,000.0K of ATRA on Sep 4, 2026; 15 funds added in the latest 13F quarter.
Nguyen AnhCo
President and CEO
SELL
2026-08-26 SECtraded 2026-08-17
5,062
$40.9K
-10.3%
Context
  • 21 earlier Form 4 trades (code P or S) here by this insider (21 sales), the last on May 18, 2026.
  • The trade is 3.8% of the 132,775 shares held after it.
  • No other insider sold within 30 days.
  • 15 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: President and CEO Nguyen AnhCo sold about $40.9K of ATRA on Aug 17, 2026; 15 funds added in the latest 13F quarter.
Nguyen AnhCo
President and CEO
SELL
2026-05-20 SECtraded 2026-05-18
5,241
$47.9K
-11.1%
Context
  • 20 earlier Form 4 trades (code P or S) here by this insider (20 sales), the last on Mar 2, 2026.
  • The trade is 3.8% of the 137,837 shares held after it.
  • 2 other insiders sold within 30 days.
  • 15 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: President and CEO Nguyen AnhCo sold about $47.9K of ATRA on May 18, 2026; 2 other insiders sold within 30 days and 15 funds added in the latest 13F quarter.
Grant-Huerta Yanina
Chief Accounting Officer
SELL
2026-05-20 SECtraded 2026-05-18
2,414
$22.0K
-11.1%
Context
  • 11 earlier Form 4 trades (code P or S) here by this insider (11 sales), the last on Mar 2, 2026.
  • The trade is 4.9% of the 49,636 shares held after it.
  • 2 other insiders sold within 30 days.
  • 15 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Chief Accounting Officer Grant-Huerta Yanina sold about $22.0K of ATRA on May 18, 2026; 2 other insiders sold within 30 days and 15 funds added in the latest 13F quarter.
Panacea Innovation Ltd
Director
SELL
2026-05-11 SECtraded 2026-05-07
313,446
$3.2M
-15.4%
Context
  • 1 earlier Form 4 trade (code P or S) here by this insider (1 buy), the last on Aug 15, 2025.
  • The trade is 31.0% of the 1,011,000 shares held after it.
  • 2 other insiders sold within 30 days.
  • 15 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Director Panacea Innovation Ltd sold about $3.2M of ATRA on May 7, 2026, the largest insider sale at the company on our record; 2 other insiders sold within 30 days and 15 funds added in the latest 13F quarter.
138 transactions on record
Since filing: total return from the first close after the filing to the latest close, dividend-adjusted. Not a forecast.
Context lines are counts over the filings above and returns from our own price history, never a price level. Not investment advice.
See all insider buying · insider selling
Showing the latest few. to see 133 more transactions and use the screener and CSV export. We store only your email; there is no password.
Seven facts, ranked against the sector · Rank is not a forecast
Insiders
net +$2.5M over 180 days
+$959.1K over 90 days · +$1.6M of it by a 10%+ holder
more than 92% of Pharma & Biotech
Congress
no House purchase disclosed in the last 12 months
Funds
15 funds bought in last quarter
below 73% of Pharma & Biotech
Revenue
-6.3% year over year
below 63% of Pharma & Biotech
Margin
27.1% net margin
more than 89% of Pharma & Biotech
Buybacks
no share repurchases reported
Short interest
7.6% of the float short (float per yahoo 2026-10-27) · 8.7 days to cover · settled 2026-10-15
below 56% of Pharma & Biotech
What changed in the last 30 days
Nothing new filed in the last 30 days

Watch ATRA

A free account keeps a watchlist and can send one email a day when insiders, funds or Congress file on the names in it. No password and no card.

The year, with the filings on it
Total return over 12 months. Each marker is a filing; hover or tap one for the detail.
-41.2%12M
-70%-38%-5%+28%2025-102025-122026-022026-042026-062026-082026-10 2026-05-07 · EcoR1 Capital, LLC bought $4.7M2026-05-07 · Panacea Innovation Ltd sold $3.2M2026-09-04 · Cherry Brian N bought $1,000.0K2026-01-12 · Huang James sold $489.0K2026-05-18 · Nguyen AnhCo sold $47.9K2026-08-17 · Nguyen AnhCo sold $40.9K2025-11-17 · Nguyen AnhCo sold $37.7K2026-05-18 · Grant-Huerta Yanina sold $22.0K2025-11-17 · Grant-Huerta Yanina sold $21.7K2026-03-02 · Grant-Huerta Yanina sold $8.1K2026-03-02 · Nguyen AnhCo sold $7.3K2026-03-02 · Nguyen AnhCo sold $6.6K2026-03-02 · Grant-Huerta Yanina sold $1.9K2025-11-17 · Grant-Huerta Yanina sold $1.1K2026-03-02 · Nguyen AnhCo sold $1.0K2025-11-17 · Grant-Huerta Yanina sold $9762025-11-17 · Nguyen AnhCo sold $7392026-03-02 · Grant-Huerta Yanina sold $5082026-03-02 · Nguyen AnhCo sold $2952026-03-02 · Grant-Huerta Yanina sold $1222026-08-26 · Nguyen AnhCo filed to sell $42.3K
Insider buyInsider sellForm 144 (planned sale)
Indexed to 100, dividend-adjusted, not a price chart. When a name files heavily, the largest trades are drawn first.

Who owns ATRA: institutional holders (13F)

13F holdings, latest reported quarter
EcoR1 Capital, LLC
1,552,000 sh
$17.8M
ADAGE CAPITAL PARTNERS GP, L.L.C.
850,000 sh
$9.8M
Point72 Asset Management, L.P.
687,718 sh
$7.9M
Redmile Group, LLC
441,701 sh
$5.1M
VANGUARD CAPITAL MANAGEMENT LLC
247,047 sh
$2.8M

Congress trades in ATRA

No Congress trades reported
No House member has disclosed a trade in this stock. See what Congress is buying.

Activist and 5% holders (13D/13G)

No 5%+ ownership filings
Nobody has filed for crossing 5%. That is a fact, not missing data.

ATRA planned insider sales (Form 144)

Notice of intent to sell, filed before any sale
Nguyen AnhCo
Filed 2026-08-26
$42.3K

ATRA mutual fund holders (N-PORT)

Funds ranked by the share of their own portfolio in this stock (N-PORT).
Ultra-Small Company Market Fund
$160.7K position · as of 2026-06-30
0.1%
VIP Disciplined Small Cap Portfolio
$186.4K position · as of 2026-06-30
0.0%
iShares Micro-Cap ETF
$197.8K position · as of 2026-06-30
0.0%
1290 VT Micro Cap Portfolio
$13.2K position · as of 2026-06-30
0.0%
VANGUARD EXTENDED MARKET INDEX FUND
$950.1K position · as of 2026-06-30
0.0%
Fidelity Extended Market Index Fund
$309.1K position · as of 2026-05-31
0.0%
SEC N-PORT, monthly, about 60 days late · funds ≥ $10M · % is the share of the fund's own portfolio
Clinical pipeline
6 registered trials, 0 still running (ClinicalTrials.gov). A status change is dated here weeks before the press release.
2
Phase 1
0 active
1
Not applicable
0 active
3
Multi-phase
0 active
Matched by sponsor name. Trials run under a subsidiary's own name are not included.
Executive pay vs shareholder return
CEO pay, headline and as actually paid, against the company's return and its chosen peers' (DEF 14A).
FY
CEO total
Actually paid
Other execs, avg
TSR
Peer TSR
2021
$5.1M
$428.1K
$2.2M
-20%
n/a
2020
$5.3M
$7.1M
$2.4M
+19%
+26%
Tagged by the company under SEC Item 402(v). Returns are cumulative from the start of the disclosure period. Green where the company beat its own peer group.
Live price
Daily candles from TradingView, under their licence. No filings marked.
Why this name is on the desk
Insiders are net buyers of their own stock.
The record shows a net $2.5M bought by insiders over 180 days, 15 funds added last quarter, $42.3K in planned Form 144 sales. Each figure is a federal filing, dated the day it went public.
Backtest this pattern Open the screener
Same sector, ranked by filing activity
Sector by SEC SIC code
UTHRCPIXMRNAREGNLLYALNYMDGLCITRDNAVRTXNUVLTWST

ATRA financials

Revenue growth
-6.3%
XBRL, annual
Net margin
27.1%
Ratios from the company's XBRL filings, latest filings
Revenue, TTM
$6.2M
four quarters, 2025-07-01 to 2026-06-30
Net margin, TTM
-269.4%
net income over revenue, 2025-07-01 to 2026-06-30
Free cash flow, TTM
-$21.9M
operating cash flow minus capex, 2025-07-01 to 2026-06-30
Debt to equity
n/a
no debt line filed
Cash flow to debt
n/a
no debt line filed
Return on equity
n/a
average equity is zero or negative
Return on assets
-57.6%
TTM net income over average of 2025-06-30 and 2026-06-30
Return on invested capital
n/a
pre-tax loss, no effective tax rate to apply
Return on capital employed
-77.9%
operating income (EBIT proxy) over average of 2025-06-30 and 2026-06-30 minus current liabilities
P/E, trailing
n/a
trailing loss, a multiple of a loss is not meaningful
Enterprise value
n/a
no debt line filed
FCF yield
-26.3%
TTM free cash flow over market value at close 2026-10-27
PEG, trailing
n/a
trailing loss, a multiple of a loss is not meaningful
Price as of 2026-10-27. Hover or tap a tile for its yearly and quarterly history.
Method
TTM is four consecutive fiscal quarters; Q4 is the year minus nine months when not filed. Returns use the average of opening and closing balances. EBIT is approximated by operating income. PEG uses trailing EPS growth.
Fundamentals
Annual figures from XBRL filings. Pick a past date to see them as known then.
2025-122024-122023-122022-12
Revenue$120.8M$128.9M$8.6M$63.6M
Operating income$35.9M-$83.4M-$276.0M-$280.5M
Net income$32.7M-$85.4M-$276.1M-$228.3M
EPS (diluted)2.57-11.41-65.19-2.24
Operating cash flow-$50.9M-$68.7M-$193.0M-$270.4M
Cash$8.5M$25.0M$25.8M$92.9M
SEC XBRL, fiscal years, as known on 2026-10-28

ATRA Stock Sonar score 5/7 axes

Find similar shapesCompare

ATRA ranks highest on insider conviction (86th percentile) and risk and compliance (54th), and lowest on institutional and government (13th), among Pharma & Biotech peers.

ProfitGrowthInsidersInstitutionsRisk
Profitability
36
Inputs
  • Return on equityaverage equity is zero or negative
  • Return on assets-57.6% · 39 pct, sector of 691
  • Return on invested capitalpre-tax loss, no effective tax rate to apply
  • Return on capital employed-77.9% · 33 pct, sector of 576
Growth
37
Inputs
  • Revenue growth, YoY-6.3% · 37 pct, sector of 505
  • Backlog growth, YoYno backlog line filed, or no year-earlier backlog
Insider conviction
86
Inputs
  • Net Form 4 buying (codes P and S), 180d$2.5M · 92 pct, sector of 428
  • Insider buyers, 180d2 · 81 pct, sector of 437
Institutional and government
13
Inputs
  • Funds adding, latest quarter15 · 27 pct, sector of 698
  • Congress net buyers, 365dno Congress trades in 365 days
  • Federal contracts, 180dno federal contracts in 180 days
  • Lobbying spend, 4 quarters$10K · 0 pct, sector of 133
Risk and compliance
54
Inputs
  • Short interest, % of float+7.0% · 50 pct, sector of 813
  • Recalls per $1B revenue, 3ynot measured for this sector, almost no peer has an event
  • EPA cases per $1B revenue, 5ynot measured for this sector, almost no peer has an event
  • New text in Risk Factors, latest 10-K+8.9% · 59 pct, sector of 511
2 not measured: Financial health, US patents
  • Financial health needs 1 of 2 inputs, 0 present: no debt line filed
  • US patents needs 1 of 2 inputs, 0 present: patent data not loaded yet

5 of 7 axes scored. Each is a percentile against sector peers (all companies when the sector is thin); higher is better. An unscored axis is unmeasured, not low. How it is scored

ATRA filings, in plain words

Are Atara Biotherapeutics insiders buying or selling ATRA?

In the 180 days to 2026-10-28, Atara Biotherapeutics insiders were net buyers, a net $2.5M: $5.7M of purchases and $3.3M of sales reported on Form 4, by 2 buyers and 3 sellers.

Are there planned insider sales of ATRA?

Yes. 1 Form 144 notice of planned insider sales was filed in the 90 days to 2026-10-28, covering $42.3K of stock; the latest, by Nguyen AnhCo, was filed 2026-08-26.

Read the full summary

In the 180 days to 2026-10-28, Atara Biotherapeutics insiders were net buyers of ATRA, a net $2.5M across purchases and sales reported on Form 4 by 2 buyers and 3 sellers. Most of that figure, $1.6M, came from a holder of 10% or more rather than an officer or director. None of the 4 insider sales was flagged as made under a Rule 10b5-1 plan. Insiders filed 1 Form 144 notice of intent to sell in the 90 days to 2026-10-28, covering $42.3K of stock. Each figure is counted from SEC and House filings as of 2026-10-28, dated the day the filing was made public.

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