SUTRO BIOPHARMA, INC. (STRO) - Dilution Analysis

Visualizing historical and potential share dilution over time

Dilution Analysis

High Risk
Significant dilution risk
Last updated: May 14, 2026

Risk Assessment Details

Potential Dilution: 43.61% of current shares
Recent Dilution: 105.09% (2 years)
Historical Dilution Factor: significant recent dilution
Outstanding Shares
17M
Potential Supply
7.2M
Additional shares possible
Splits
1 Split 1 Reverse
Past 2 years

Summary

STRO currently has 16.6M outstanding shares. with moderate dilution risk from 7.23M authorized shares representing 43.6% potential dilution. The company has significantly diluted shareholders by 105.09% over the past 2 years, indicating aggressive capital raising. Recent corporate actions include 1 stock split (positive for accessibility) and 1 reverse split (concerning signal).

Share Structure Timeline

Outstanding Shares
Total Supply

Historical Data Points

Date Event Outstanding Supply
May 14, 2026

10-Q filing | 16.6M shares outstanding

17M 7.2M
Mar 23, 2026

S-3 filing: Sutro Biopharma, Inc. is filing an S-3 to offer common stock, preferred stock, debt securities, warrants, subscription rights, and units up to an aggregate amount of $300 million.

8.6M 15M
Dec 03, 2025
Stock Split

8-K filing: Stock split 1-for-10 | Outstanding: 84,869,864 → 8,519,392

8.5M 11M
Nov 06, 2025

10-Q filing | 84.9M shares outstanding

85M 110M
Aug 07, 2025

10-Q filing | 84.6M shares outstanding

85M 110M
May 08, 2025

10-Q filing | 83.1M shares outstanding

83M 110M
Mar 13, 2025

10-K filing | 76.8M shares outstanding

77M 110M
Nov 13, 2024

10-Q filing | 82.0M shares outstanding

82M 110M
Aug 13, 2024

10-Q filing | 81.2M shares outstanding

81M 110M
May 13, 2024

10-Q filing | 81.8M shares outstanding

82M 110M
Apr 02, 2024

8-K filing: Sutro Biopharma, Inc. entered into an underwriting agreement to issue and sell 14,478,764 shares of its common stock at $5.18 per share, with gross proceeds estimated at $75.0 million, intending to use the net proceeds for general corporate purposes. ($75.0M proceeds)

60M 130M
Apr 02, 2024

8-K filing: Sutro Biopharma, Inc. entered into an agreement with Ipsen Biopharmaceuticals, Inc. for the purchase of 4,827,373 shares of Sutro's common stock at a price representing a 17% premium to the VWAP for $25 million. ($25.0M proceeds)

60M 130M
Mar 25, 2024

10-K filing | 60.2M shares outstanding

60M 130M
Nov 13, 2023

S-3 filing: Sutro Biopharma, Inc. may offer up to $300.0 million aggregate dollar amount of shares of its common stock or preferred stock, debt securities, warrants to purchase its common stock, preferred stock or debt securities, subscription rights to purchase its common stock, preferred stock or debt securities and/or units consisting of some or all of these securities.

60M 130M
Nov 13, 2023

10-Q filing | 60.6M shares outstanding

61M 130M
Aug 10, 2023

10-Q filing | 60.3M shares outstanding

60M 0
May 15, 2023

10-Q filing | 58.7M shares outstanding

59M 0
Mar 30, 2023

10-K filing | 60.2M shares outstanding

60M 0
Nov 08, 2022

10-Q filing | 52.3M shares outstanding

52M 0
Aug 08, 2022

10-Q filing | 47.0M shares outstanding

47M 0
May 09, 2022

10-Q filing | 46.9M shares outstanding

47M 0
Mar 01, 2022

POS AM filing: Sutro Biopharma, Inc. may offer up to $350,000,000 aggregate dollar amount of shares of their common stock or preferred stock, debt securities, warrants to purchase their common stock, preferred stock or debt securities, subscription rights to purchase their common stock, preferred stock or debt securities and/or units consisting of some or all of these securities. Common stock offered by them having an aggregate offering price of up to $100 million through an at the market offering.

46M 54K
Feb 28, 2022

10-K filing | 46.4M shares outstanding

46M 0
Nov 10, 2021

10-Q filing | 46.2M shares outstanding

46M 0
Aug 09, 2021

10-Q filing | 46.1M shares outstanding

46M 0
May 07, 2021

10-Q filing | 46.1M shares outstanding

46M 0
Mar 18, 2021

10-K filing | 45.9M shares outstanding

46M 0
Dec 09, 2020

8-K filing: Sutro Biopharma, Inc. entered into an underwriting agreement to issue and sell 6,000,000 shares of its common stock at a public offering price of $21.00 per share, with an option for the underwriters to purchase up to an additional 900,000 shares, with estimated net proceeds of approximately $118.0 million. ($126.0M proceeds)

38M 0
Nov 05, 2020

10-Q filing | 37.9M shares outstanding

38M 0
Aug 06, 2020

10-Q filing | 35.9M shares outstanding

36M 0
May 12, 2020

8-K filing: Sutro Biopharma, Inc. entered into an underwriting agreement to issue and sell 11,000,000 shares of its common stock at a price of $7.75 per share, with an option for the underwriters to purchase an additional 1,650,000 shares. ($85.25M proceeds)

23M 0
May 11, 2020

10-Q filing | 23.2M shares outstanding

23M 0
Mar 16, 2020

10-K filing | 23.1M shares outstanding

23M 0
Mar 03, 2020

8-K filing: Sutro Biopharma, Inc. issued warrants to lenders, Oxford Finance LLC and Silicon Valley Bank, exercisable for 81,257 shares of the company's common stock at an exercise price of $9.23 per share, in connection with a loan and security agreement.

N/A 0
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