Sutro Biopharma
STRO on Nasdaq. Sutro Biopharma develops antibody drug conjugates for cancer patients but sells nothing yet. Market value $251m.
Price checks use the past 12 months to June 2026. Some use the latest annual report instead, as marked. Quality checks use five annual reports, the latest for the year to December 2025.
We can't read total debt from the filing, so debt is left out.
Cash flow or capital spending isn't reported, so free cash flow is unknown.
Should I look at this?
Not a fit for our list right now
Why it could be worth it
Nothing stands out yet.
See Health care stocks that passed both tests
This is not advice. Check the numbers below.
We could not compute this from the filings.
The filings do not give us enough to work this out.
Each dollar kept in the business earns -55 cents a year. Above 10 is good.
Quality score: 30 of 100. Price score: 16 of 100. Our list needs 70 on quality and 60 on price.
$14.45 a share, 102% above its 1-year low
Over the past year the price has ranged from $7.15 to $43.85.
Pays no dividend
Prices from Tuesday’s close (6 October).
Five years of cash, in billions
| Revenue | |||||
| Revenue | $62m | $68m | $154m | $62m | $102m |
| Operating margin | |||||
| Operating margin | -159.2% | -190.3% | -58.1% | -384.3% | -154.5% |
| Debt to equity | |||||
| Debt to equity | 0.10 | 0.07 | 0.03 | n/a | n/a |
| Shares outstanding | |||||
| Shares outstanding | 0.06bn | 0.06bn | 0.08bn | 0.09bn | 0.02bn |
Health checks
- Free cash flow positiveNot enough data
- Accounting looks honest (Beneish)Not enough data
- Financial strength (Piotroski)2 of 7 checks we could run
- Profit backed by cash (accruals)Yes
- DebtUnknown
- Revenue growth, five yearsStrong, 19.1% a year
- Buying back its own sharesYes, 71% fewer since 2021
The quarter to June 2026
How the business did, compared with the same quarter a year earlier.
- Sales: $10 million last quarter, down 85% on a year ago.
- A loss of $39 million, compared with a loss of $11 million a year ago.
- It loses 320 cents on each $1 of sales, compared with 196 cents a year earlier.
- 95% more shares than a year ago. Each share owns a bit less of the company.
- Sales grew on a year ago in 1 of the last 4 quarters.
| Quarter to | Amount |
|---|---|
| September 2024 | $9m |
| December 2024 | $15m |
| March 2025 | $17m |
| June 2025 | $64m |
| September 2025 | $10m |
| December 2025 | $12m |
| March 2026 | $15m |
| June 2026 | $10m |
| Quarter to | Amount |
|---|---|
| September 2024 | -$49m |
| December 2024 | -$72m |
| March 2025 | -$76m |
| June 2025 | -$11m |
| September 2025 | -$57m |
| December 2025 | -$47m |
| March 2026 | -$38m |
| June 2026 | -$39m |
From the company's quarterly reports to the SEC.
Dates
- Next results (estimated)
- n/a
- Last annual report (10-K)
- 23 March 2026
- Next quarterly (estimated, 10-Q)
- 11 November 2026
Who owns it
None of the long-term investors we follow own it. 100 funds in all.
Largest holders overall
- Perceptive Advisors$43mAdded
- BVF$42m
- Affinity Asset Advisors$39mAdded
- BlackRock$37mAdded
- Samsara Biocapital$35m
- Kynam Capital Management, LP$29m
- Orbimed Advisors$25mCut
- Balyasny Asset Management L.P.$24mAdded
- Vanguard Capital Management$23mCut
- Eventide Asset Management$19mCut
From 13F filings for the quarter ended 30 June 2026.
Big holders and activists
7 investors own more than 5%.
- Perceptive Advisors LLCPassive investorat least 7.9%+2.5 pts(filed with 2 related holders)Since 30 June 2026
- Affinity Healthcare Fund, LPPassive investor7.8%Since 16 October 2025
- BVF PARTNERS L P/ILPassive investorat least 7.6%(filed with 9 related holders)Since 10 February 2026
- Affinity Asset Advisors, LLCPassive investorat least 6.5%−2.3 pts(filed with 1 related holder)Since 31 March 2026
- BlackRock, Inc.Passive investor6.4%+3.9 ptsSince 30 June 2026
- Srinivas AkkarajuPassive investorat least 6.4%(filed with 4 related holders)Since 11 February 2026
- Kynam Capital Management, LPPassive investorat least 5.3%−1.2 pts(filed with 2 related holders)Since 31 March 2026
- The Vanguard GroupPassive investorSold down below 5%Since 30 June 2025
- Point72 Asset Management, L.P.Passive investorSold down below 5%Since 30 June 2026
- Millennium Management LLCPassive investorSold down below 5%Since 31 March 2026
- SUVRETTA CAPITAL MANAGEMENT, LLCPassive investorSold down below 5%Since 31 December 2025
- RA Capital Management, L.P.Passive investorSold down below 5%Since 30 June 2025
| Holder | Stake | Since | |
|---|---|---|---|
Perceptive Advisors LLC Passive investor | at least 7.9%+2.5 pts (filed with 2 related holders) | 30 June 2026 | |
Affinity Healthcare Fund, LP Passive investor | 7.8% | 16 October 2025 | |
BVF PARTNERS L P/IL Passive investor | at least 7.6% (filed with 9 related holders) | 10 February 2026 | |
Affinity Asset Advisors, LLC Passive investor | at least 6.5%−2.3 pts (filed with 1 related holder) | 31 March 2026 | |
BlackRock, Inc. Passive investor | 6.4%+3.9 pts | 30 June 2026 | |
Srinivas Akkaraju Passive investor | at least 6.4% (filed with 4 related holders) | 11 February 2026 | |
Kynam Capital Management, LP Passive investor | at least 5.3%−1.2 pts (filed with 2 related holders) | 31 March 2026 | |
The Vanguard Group Passive investor | Sold down below 5% | 30 June 2025 | |
Point72 Asset Management, L.P. Passive investor | Sold down below 5% | 30 June 2026 | |
Millennium Management LLC Passive investor | Sold down below 5% | 31 March 2026 | |
SUVRETTA CAPITAL MANAGEMENT, LLC Passive investor | Sold down below 5% | 31 December 2025 | |
RA Capital Management, L.P. Passive investor | Sold down below 5% | 30 June 2025 |
From Schedule 13D and 13G filings: anyone owning more than 5% must file one.
What insiders did
In the last 12 months, 5 insiders bought $89,601 of shares on the open market.
- Pauling DavidChief Admin. Ofcr. & GCBought
- Date
- 15 October 2025
- Shares
- 12,504
- Price
- $0.80
- Value
- $10,003
- Gerber Hans-PeterCHIEF SCIENTIFIC OFFICERBought
- Date
- 15 October 2025
- Shares
- 17,000
- Price
- $0.80
- Value
- $13,600
- Chung JaneChief Executive Officer, DirectorBought
- Date
- 15 October 2025
- Shares
- 12,500
- Price
- $0.80
- Value
- $10,000
- Chow Gregory K.CFOBought
- Date
- 15 October 2025
- Shares
- 19,750
- Price
- $0.81
- Value
- $15,998
- MATSUI CONNIEDirectorBought
- Date
- 15 October 2025
- Shares
- 50,000
- Price
- $0.80
- Value
- $40,000
| Date | Who | Did | Shares | Price | Value |
|---|---|---|---|---|---|
| 15 October 2025 | Pauling David Chief Admin. Ofcr. & GC | Bought | 12,504 | $0.80 | $10,003 |
| 15 October 2025 | Gerber Hans-Peter CHIEF SCIENTIFIC OFFICER | Bought | 17,000 | $0.80 | $13,600 |
| 15 October 2025 | Chung Jane Chief Executive Officer, Director | Bought | 12,500 | $0.80 | $10,000 |
| 15 October 2025 | Chow Gregory K. CFO | Bought | 19,750 | $0.81 | $15,998 |
| 15 October 2025 | MATSUI CONNIE Director | Bought | 50,000 | $0.80 | $40,000 |
From Form 4 filings: insiders must report trades in their own company's shares within two days.
What could go wrong
- It owes more than it owns on paper (negative equity). Often that's from borrowing to buy back shares.
Whether the price already reflects the risks is what the deep dive is for.
The deep dive
Everything above is arithmetic on public filings. The deep dive reads the last ten years of annual reports, the proxy statements, and the earnings calls, then argues the case the way Buffett, Klarman, and Hohn would, and checks every claim against the source.
- What the business is worth, as a range, and the margin of safety at today’s price
- Prices to start buying, buy, and buy hard
- The three things that would make this a mistake
- Every number footnoted to the filing it came from
Your first deep dive is free.
Not advice. Numbers on this page come from SEC filings and are updated each night; prices are updated again after the US market closes. The five-year figures are rounded.