What is the 13F Pro Quality Score for ATRA?

13F Pro ranks Atara Biotherapeutics, Inc. (ATRA) on the 13F Pro Quality Score, a 0–100 composite of 32 fundamental signals including return on invested capital, free cash flow consistency, balance-sheet strength, earnings quality, growth durability, and valuation discipline. The score refreshes after each 10-K and 10-Q filing on SEC EDGAR. View ATRA's current score at https://13fpro.ai/research/ATRA (free sign-up required for the full ranking).

Which hedge funds own the most ATRA stock?

Based on the most recent Form 13F-HR filings on SEC EDGAR, the largest reported institutional holders of ATRA include ADAGE CAPITAL PARTNERS GP, L.L.C., Redmile Group,, MACKENZIE FINANCIAL. Holdings are reported quarterly within 45 days of quarter-end and updated on https://13fpro.ai/research/ATRA as soon as new 13F filings post.

Where does 13F Pro source ATRA data?

All Atara Biotherapeutics, Inc. fundamentals and ownership data come directly from SEC EDGAR. Atara Biotherapeutics, Inc. files with the SEC under CIK 1604464. 13F Pro ingests XBRL financial facts from 10-K and 10-Q filings, Form 13F-HR institutional holdings, and Form 4 insider transactions, with no third-party rewrites or estimates.

What sector is ATRA in?

Atara Biotherapeutics, Inc. (ATRA) is classified in the Healthcare sector. 13F Pro publishes sector-level fund flow analysis and quality leaders at https://13fpro.ai/research/sector/healthcare.

How often is ATRA research updated on 13F Pro?

ATRA's fundamentals refresh within hours of each new 10-K or 10-Q filing on SEC EDGAR. Institutional ownership updates after each quarterly 13F filing window. Insider transactions update after each Form 4 filing. The 13F Pro Quality Score recalculates after every fundamentals refresh.

Atara Biotherapeutics, Inc.(ATRA)Stock Analysis

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13F Pro Quality Score

63.0/100

Rank #708 of 2,879 stocksTOP 25%

View Healthcare peers →

Rankings refresh quarterly once 80% of peers have filed (~45 days after quarter-end). Next update: ~Aug 14, 2026.

Revenue Growth

95.4/100

Profitability

90.8/100

Balance Sheet

99.9/100

Earnings Quality

30.0/100

Free Cash Flow

10.4/100

Institutional Flow

76.7/100

Revenue Scale

19.4/100

Dilution Risk

19.6/100

ATRA Stock Analysis & AI Quality Score

AI stock analysis and institutional research for Atara Biotherapeutics, Inc. (ATRA), a Healthcare sector company. 13F Pro's AI-powered ranking engine scores ATRA at 63.0/100 on a 32-signal composite quality model, placing it at rank #708 of 2,879 stocks — the top 25% of the AI-ranked universe. ATRA scores in the top quartile across balance sheet strength (99.9), revenue growth (95.4), profitability (90.8). Areas of concern include free cash flow (10.4) and revenue scale (19.4), which score below median versus the broader universe. Shareholder dilution risk is elevated at 19.6/100, reflecting ongoing share issuance or stock-based compensation. Based on the latest XBRL financial filings (Q1 2026), Atara Biotherapeutics, Inc. reports quarterly revenue of $516.0K, net income of $-4.1M, free cash flow of $-3.1M. Top institutional holders of ATRA by reported 13-F value include ADAGE CAPITAL PARTNERS GP, L.L.C., Redmile Group,, MACKENZIE FINANCIAL, based on the most recent SEC filings. ATRA trades on the Nasdaq exchange and files with the SEC under CIK 1604464. 13F Pro's AI research platform runs 10 specialized AI analysts — value, growth, momentum, macro, and activist specialists — that debate ATRA daily and publish AI-generated analysis with cited SEC sources. The platform aggregates historical XBRL financial facts, 10-Q and 10-K filings, insider Form 4 transactions, and institutional 13-F holdings for Atara Biotherapeutics, Inc. directly from SEC EDGAR. Atara Biotherapeutics, Inc.'s 13F Pro composite quality score has ranged between 18 and 63 since 2024, currently 63.0 — an improving long-term trajectory across 16 quarterly and live scoring snapshots.

✦

Fun facts about Atara Biotherapeutics, Inc.

Quirks, history, and lore behind ATRA — the kind of stuff that makes a stock memorable.

1
The Basics
U.S. clinical-stage biopharmaceutical company · listed on Nasdaq · headquartered in South San Francisco, the self-proclaimed biotech capital of the world.
2
The Numbers
A classic pre-revenue biotech — the company runs on capital raises and grants rather than product sales, with a market cap in the low hundreds of millions at its peak.
3
The History
Founded in the 2010s, it was built around a single bold scientific bet: that donor-derived T-cell therapies could fight diseases that conventional drugs could not.
4
The Secret
Its core platform targets Epstein-Barr virus — the ubiquitous pathogen linked to certain cancers and autoimmune diseases — a target most drugmakers have largely ignored.
5
The Lore
Its lead program pursued EBV-positive post-transplant lymphoproliferative disease, a rare and often fatal condition in immunocompromised patients — niche doesn't begin to cover it.
6
The Giveaway
The ticker ATRA is a clue in itself — this is Atara, the biotech named after a Hebrew word, betting everything on off-the-shelf T-cell medicine for EBV-driven illness.

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Revenue

Q1 2026

$516.0K

Net Income

Q1 2026

$-4.1M

Free Cash Flow

Q1 2026

$-3.1M

Revenue & Net Income

Earnings Per Share

Key Financials Over Time

Export Financial Table · Pro+

Revenue

$8.6MFY 2023

FY18 —FY20 —FY21 —FY23 $8.6M

Net Income

+18.8% YoY

$-276.1MFY 2023

FY18 $-230.7MFY20 $-306.6MFY21 $-340.1MFY23 $-276.1M

Operating Income

+18.9% YoY

$-276.0MFY 2023

FY18 $-237.1MFY20 $-309.1MFY21 $-340.5MFY23 $-276.0M

EPS (Diluted)

-1695.9% YoY

$-65.19FY 2023

FY18 —FY20 $-4.15FY21 $-3.63FY23 $-65.19

Total Assets

-64.6% YoY

$165.5MFY 2023

FY18 $391.8MFY20 $588.1MFY21 $468.1MFY23 $165.5M

Op. Cash Flow

+12.5% YoY

$-193.0MFY 2023

FY18 $-179.8MFY20 $-180.8MFY21 $-220.5MFY23 $-193.0M

Metric	FY 2023	FY 2021	FY 2020	FY 2018	FY 2016	FY 2015
Revenue	$8.6M	—	—	—	—	—
Net Income	$-276.1M +18.8%	$-340.1M -10.9%	$-306.6M -32.9%	$-230.7M -191.8%	$-79.0M -38.1%	$-57.2M
Operating Income	$-276.0M +18.9%	$-340.5M -10.2%	$-309.1M -30.3%	$-237.1M -191.9%	$-81.2M -39.0%	$-58.4M
EPS (Diluted)	$-65.19 -1695.9%	$-3.63 +12.5%	$-4.15	—	—	—
Total Assets	$165.5M -64.6%	$468.1M -20.4%	$588.1M +50.1%	$391.8M +48.5%	$263.9M -18.8%	$325.0M
Operating Cash Flow	$-193.0M +12.5%	$-220.5M -22.0%	$-180.8M -0.5%	$-179.8M -199.5%	$-60.0M	—

AI Insight: ATRA Financial Trends

Revenue collapsed 99% from Q1 2025 peak of $98M to $1M in Q1 2026, erasing profitability and burning cash.

• Q1 2025 showed $98M revenue and $38M net income; by Q1 2026 revenue fell to $1M with $4M net loss.

• Operating cash outflow averaged $11M per quarter Q2 2024–Q4 2024, then $6M average Q2 2025–Q1 2026.

• Equity deficit narrowed from $111M (Q2 2024) to $37M (Q1 2026), driven by Q1 2025 profitability spike.

⚠ Revenue sustainability critical: $98M Q1 2025 followed by sequential declines; Q1 2026 at $1M signals potential product/market failure.

⚠ Cash burn resumed post-Q2 2025; negative operating cash flow every quarter since Q2 2025 despite equity improvement.

AI Insight: ATRA Ratio Trends

Atara swung from Q1 2025 profitability (39.5% op margin) to severe losses in Q4 2025 (–160.7%), with TTM ROA at –47.3%.

• Operating margin collapsed from +39.5% in Q1 2025 to –160.7% in Q4 2025, a 200pp reversal in nine months.

• ROA deteriorated from +25.9% in Q2 2025 to –82.9% in Q1 2026, indicating sustained cash burn.

• Company posted losses in 6 of last 9 quarters; only Q1 2025 showed profitability.

⚠ Q3–Q4 2025 deterioration suggests material operational disruption or one-time charge; investigate root cause.

⚠ Sustained negative margins and ROA raise going-concern questions; balance sheet leverage data unavailable.

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Available Research

13F Pro tracks comprehensive data for Atara Biotherapeutics, Inc. including:

SEC EDGAR filings (10-K, 10-Q, 8-K)

XBRL financial facts (revenue, EPS, margins)

Insider transactions (Form 4)

Institutional 13F holdings

Quality rankings (32 signals)

AI analyst debates & daily meetings

Historical financial trends

Peer comparison & sector analysis

Top Institutional Holders of ATRA

ADAGE CAPITAL PARTNERS GP, L.L.C.
$3.3M700,000 sh
Redmile Group, LLC
$2.1M441,701 sh
MACKENZIE FINANCIAL CORP
$1.5M313,620 sh
VANGUARD CAPITAL MANAGEMENT LLC
$1.0M217,862 sh
Point72 Asset Management, L.P.
$918.9K194,264 sh
EcoR1 Capital, LLC
$471.1K99,593 sh
BlackRock, Inc.
$373.8K79,022 sh
GEODE CAPITAL MANAGEMENT, LLC
$313.0K66,146 sh
UBS Group AG
$236.8K50,070 sh
STALEY CAPITAL ADVISERS INC
$236.5K50,000 sh

Fund	Value	Shares
ADAGE CAPITAL PARTNERS GP, L.L.C.	$3.3M	700,000
Redmile Group, LLC	$2.1M	441,701
MACKENZIE FINANCIAL CORP	$1.5M	313,620
VANGUARD CAPITAL MANAGEMENT LLC	$1.0M	217,862
Point72 Asset Management, L.P.	$918.9K	194,264
EcoR1 Capital, LLC	$471.1K	99,593
BlackRock, Inc.	$373.8K	79,022
GEODE CAPITAL MANAGEMENT, LLC	$313.0K	66,146
UBS Group AG	$236.8K	50,070
STALEY CAPITAL ADVISERS INC	$236.5K	50,000

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Is ATRA a good stock to buy?

13F Pro's AI-powered analysis of Atara Biotherapeutics, Inc. (ATRA) draws on SEC EDGAR-sourced fundamentals, institutional 13F holdings, and insider Form 4 transactions in the Healthcare sector (listed on Nasdaq). The 32-signal AI Quality Score, current rank, and full bull/bear verdict for ATRA are available on the ATRA stock profile dashboard — with the same data, AI insights, ratios, and institutional activity refreshed after every 10-K, 10-Q, 13F, and Form 4 filing.

Which hedge funds own ATRA?

Institutional investors are required to disclose their holdings quarterly via SEC Form 13F. 13F Pro aggregates these filings to show which hedge funds, mutual funds, and asset managers are buying or selling ATRA. Combined with insider transaction data from Form 4 filings and AI-powered analysis from 10 specialized research agents, 13F Pro provides a comprehensive view of Atara Biotherapeutics, Inc.'s investment landscape.