Stock Analysis
Data Source: SEC EDGAR 13F
Updated Hourly

Atara Biotherapeutics Inc (ATRA)

32 + Investors. Track Smart Money conviction in ATRA. See who's accumulating, reducing, or initiating positions.

Current Price
-- USD
Analyst Target
-- (0 analysts)
Upside
0.00%
Net Flow Q/Q
↓ -10
Streak
1Q ▼
Buyers last Q
46%

Smart Money Signals — ATRA

Based on 32 hedge funds · latest filing: 2026 Q1 · updated quarterly

📉

Selling streak — 1 quarter in a row

last 6Q
For 1 consecutive quarter, more hedge funds reduced or closed their ATRA positions than added to them. Sustained institutional selling is a meaningful warning sign — these are professionals with deep research teams collectively deciding to exit.
📊

High ownership — 76% of 3.0Y peak

76% of all-time peak
32 funds currently hold this stock — 76% of the 3.0-year high of 42 funds (reached 2025 Q4). Ownership is elevated but not yet at maximum concentration. Room to grow, but watch if the trend reverses.
📉

Outflows — 11% fewer funds vs a year ago

fund count last 6Q
4 fewer hedge funds hold ATRA compared to a year ago (-11% decline). When institutions consistently reduce their exposure, it's worth exploring the underlying fundamental reasons driving them away.
🟠

More sellers than buyers — 46% buying

16 buying19 selling
Last quarter: 19 funds reduced or exited vs 16 that bought or added. When more than half of active funds are selling, it's a caution flag — especially if the stock price hasn't moved down yet.
➡️

Steady new buyers — ~6 new funds per quarter

new funds entering per quarter
Funds opening this position for the first time: 4 → 8 → 7 → 6. A stable flow of new institutional buyers suggests ongoing interest without signs of either acceleration or slowdown.
🔄

Mostly new holders — 25% entered in last year

■ 3% conviction (2yr+) ■ 72% medium ■ 25% new
Only 1 funds (3%) have held >2 years. The majority of current holders are relatively new to the position. New holders tend to sell faster when prices drop — a shallow conviction base that could amplify any sell-off.
💎

Buying through price weakness — shares +25%, value -69%

Value
-69%
Shares
+25%
Last quarter: funds added +25% more shares while total portfolio value only changed -69%. Institutions were buying while the price was falling — a high-conviction accumulation signal. They're deliberately loading up on the dip.
➡️

Steady discovery — ~6 new funds/quarter

4 → 4 → 8 → 7 → 6 new funds/Q
New funds entering each quarter: 4 → 8 → 7 → 6. Consistent flow of new institutional buyers without clear acceleration or slowdown.
📊

Mixed cohorts — 3% veterans, 31% new entrants

■ 3% veterans ■ 66% 1-2yr ■ 31% new
Of 32 current holders: 1 (3%) held 2+ years, 21 held 1–2 years, 10 (31%) entered in the past year. Balanced distribution — some institutional memory, some recent momentum buyers.
📋

Smaller funds dominant — 11% AUM from top-100

11% from top-100 AUM funds
14 of 31 holders rank in the top 100 by AUM, but together hold only 11% of total institutional value. The stock is held primarily by smaller and mid-sized funds.
2.7
out of 10
Low Exit Risk
Exit risk score 2.7/10 — low institutional crowding. Ownership is below peak levels, holder base is relatively sticky, and buying momentum is positive.

Methodology note: these Smart Money cards use consecutive 13F disclosure snapshots, not trade-by-trade execution data. "Buying", "selling", "new holders", and "trimmed" refer to quarter-over-quarter changes in reported holders, aggregate shares, or disclosed position values between filings. They are useful for ownership regime analysis and crowding, but they do not imply exact trade timing on the filing date.

Institutional Sentiment Summary — ATRA

In 2026 Q1, 16 hedge funds were net buyers of ATRA (6 opened a new position, 10 added to an existing one), while 19 reduced or exited (3 trimmed, 16 sold completely) — a 46% buyer ratio, indicating roughly balanced activity. Net fund flow last quarter: -10 funds (more exits than new entries). Total institutional holders: 32.

Hedge Fund Ownership: ATRA

How many hedge funds hold ATRA — quarterly history vs. share price
Quarterly hedge fund ownership of ATRA vs. share price

Market Analysis: ATRA

Analyst Price Targets

Avg. Price Target
--

Analyst Recommendations

Stock Performance

Real-time

Company Profile: ATRA

-- --

Institutional ownership data sourced from SEC EDGAR Form 13F-HR filings.

Is It Too Late to Buy Atara Biotherapeutics Inc (ATRA) Based on Hedge Fund 13F Filings?

Signal Freshness measures how much ATRA has moved relative to its sector benchmark (XLV) since the 2026 Q1 13F filing. A stock that has barely outrun its sector is still a relatively fresh entry point — the fund's thesis has not yet been priced in by the broader market.

Since Quarter End March 31, 2026 · 84d ago
ATRA
+124.3%
XLV
+2.8%

ATRA outperformed XLV by +121.5% since March 31, 2026.

Since 13F Filing Date May 15, 2026 · 39d ago
ATRA
+10.8%
XLV
+3.9%

Since the filing became public, ATRA outperformed XLV by +6.9% .

Interpretation: The stock is tracking its sector benchmark closely. The signal remains fresh and the entry point is still near the fund's implied reference. Learn more →

Smart Money Signal ?
Limited Smart Money Interest

No strong consensus or elite conviction detected among institutional holders.

6 top-rated funds 0 high-conviction
Consensus
3.7
/ 10
breadth
×
Elite
0.0
/ 10
conviction
Hedge Fund Positioning: ATRA
32 + Investors

Track Smart Money conviction in ATRA. See who's accumulating, reducing, or initiating positions.

Metric All 13F Filers (2026 Q1) Prior (2025 Q4) Change
Funds Holding 32 42 -23.81%
13F Shares 3M 2M 25.02%
Total Value $12M $37M -68.97%
New Positions 6 7 -1
Increased Positions 10 12 -2
Closed Positions 16 2 +14
Reduced Positions 3 8 -5
Total Calls 1 1 -
Total Puts 0 0 -
PUT/CALL Ratio 0.0 0.0 Bullish

Statistics: ATRA

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Valuation Measures Data as of: --

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Enterprise Value/EBITDA --
Beta (5Y Monthly) --
Short Ratio (Days to Cover) --
Short % of Float --

Financial Highlights

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Institutional Holders (2026 Q1)

32 + investors

Explore institutional interest and hedge fund ownership dynamics. Analyze portfolio weights, new positions, and conviction trends in ATRA. Verified SEC 13F-HR filings.

QUARTER:
Top 25 ATRA holders by conviction (% of portfolio weight) — 2026 Q1 · Source: SEC Form 13F
# Investor % of Portfolio Shares Mkt Value
1 Redmile Group, LLC 0.14% 441,701 $2.1M
2 EcoR1 Capital, LLC 0.02% 99,593 $471K
3 Staley Capital Advisers Inc 0.01% 50,000 $236K
4 Adage Capital Partners GP, L.L.C. 0.01% 700,000 $3.3M
5 Bridgeway Capital Management, LLC 0.00% 32,691 $155K
6 Mackenzie Financial Corp 0.00% 313,620 $1.5M
7 Point72 Asset Management, L.P. 0.00% 194,264 $919K
8 SBI Securities Co., Ltd. 0.00% 1,574 $7K
9 KERR FINANCIAL PLANNING Corp 0.00% 24 —
10 Millennium Management LLC 0.00% 47,689 $226K
11 Vanguard Fiduciary Trust Co 0.00% 33,621 $159K
12 UBS Group AG 0.00% 50,070 $237K
13 Vanguard Capital Management LLC 0.00% 217,862 $1.0M
14 Banque Transatlantique SA 0.00% 176 —
15 Jane Street Group, LLC 0.00% 33,870 $160K
16 Raiffeisen Bank International AG 0.00% 200 —
17 BlackRock, Inc. 0.00% 79,022 $374K
18 Fmr LLC 0.00% 16,238 $77K
19 Royal Bank of Canada 0.00% 4,319 $20K
20 Morgan Stanley 0.00% 9,169 $43K
21 Jones Financial Companies Lllp 0.00% 703 $3K
22 Rhumbline Advisers 0.00% 175 —
23 Wells Fargo & Company/Mn 0.00% 251 $1K
24 Western Wealth Management, LLC 0.00% 1 —
25 BNP Paribas Financial Markets 0.00% 58 —
Investor Ownership
History 		% of Portfolio Prev % Rank Conviction Avg Buy Price 13F Score™ 3Y / 7Y Sell Timing Shares Mkt Value Change Change % Source Quarter Filed

Frequently Asked Questions — Atara Biotherapeutics Inc (ATRA)

What does the Smart Money Trend signal show for ATRA?

Selling streak — 1 quarter in a row: For 1 consecutive quarter, more hedge funds reduced or closed their ATRA positions than added to them. Sustained institutional selling is a meaningful warning sign — these are professionals with deep research teams collectively deciding to exit.

What is the institutional breadth score for ATRA?

More sellers than buyers — 46% buying: Last quarter: 19 funds reduced or exited vs 16 that bought or added. When more than half of active funds are selling, it's a caution flag — especially if the stock price hasn't moved down yet.

What is the fund quality score for ATRA holders?

Smaller funds dominant — 11% AUM from top-100: 14 of 31 holders rank in the top 100 by AUM, but together hold only 11% of total institutional value. The stock is held primarily by smaller and mid-sized funds.

How long have hedge funds held ATRA?

Mostly new holders — 25% entered in last year: Only 1 funds (3%) have held >2 years. The majority of current holders are relatively new to the position. New holders tend to sell faster when prices drop — a shallow conviction base that could amplify any sell-off.

Is it too late to buy Atara Biotherapeutics Inc (ATRA) following the 2026 Q1 hedge fund 13F filings?

As of today, ATRA has moved +10.8% since the 2026 Q1 13F filing date (May 15, 2026), compared to +3.9% for the XLV sector ETF — an outperformance of +6.9%. Since the quarter end (March 31, 2026), ATRA has gained +124.3% vs +2.8% for XLV. The stock is tracking its sector benchmark closely. The signal remains fresh and the entry point is still near the fund's implied reference.

Where does this institutional ownership data come from?

All holdings data is sourced from SEC Form 13F filings, which institutional investment managers with over $100 million in assets are required to submit quarterly. Data is parsed directly from SEC EDGAR.

Disclaimer: The information on this page is for informational purposes only and does not constitute investment advice, a recommendation, or an offer to buy or sell any security. Institutional holdings data is sourced from SEC Form 13F filings and reflects positions as of the filing date. Past performance of any fund or portfolio is not indicative of future results. 13Foresight is not a registered investment adviser. Always conduct your own due diligence before making investment decisions.

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