Sutro Biopharma (STRO) Options Chain
NASDAQ: STROHealth CareBiotechnology: Biological Products (No Diagnostic Substances)USD
At close: Oct 8, 4:00 PM ET · Delayed 15 min
After hours: 15.32 0.00%
Expiration date
- Expiration
- Oct 16, 2026
- Days to expiration
- 8
- Share price
- $15.32
- Put/call ratio (OI)
- 0.01
- Put/call ratio (volume)
- 0.80
- ATM implied volatility
- 215.4%
- Expected move
- ±$4.89
- Open interest (C / P)
- 977 / 12
STRO options summary
The STRO options chain for the October 16, 2026 expiration lists 6 call and 4 put contracts, with 8 days until expiration. Open interest stands at 977 calls and 12 puts, a put/call ratio of 0.01, which is tilted bullish, with calls outnumbering puts. At-the-money implied volatility near the $15.00 strike is 215.4%, which implies the market expects a move of about ±$4.89 (31.9%) in Sutro Biopharma stock by expiration.
The most open interest sits at the $15.00 call (681 contracts) and the $17.50 put (10 contracts).
Summary generated from market data by MetaCap's automated system. Methodology
STRO options chain · October 16, 2026
| Calls | Puts | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Last | Bid | Ask | Strike | Bid | Ask | Last | |||||
| — | — | — | 12.50 | 0.00 | 3.70 | 0.47 | |||||
| 2.00 | 0.00 | 4.40 | 15.00 | — | — | — | |||||
| 0.30 | 0.00 | 1.35 | 17.50 | 0.50 | 4.90 | 2.22 | |||||
| 0.40 | 0.00 | 3.60 | 20.00 | 3.00 | 6.50 | 4.75 | |||||
| 0.50 | 0.00 | 3.60 | 22.50 | 5.50 | 9.00 | 8.14 | |||||
| 1.00 | 0.00 | 3.60 | 25.00 | — | — | — | |||||
| 1.85 | 0.00 | 2.25 | 30.00 | — | — | — | |||||
In-the-money callsIn-the-money puts. IV = implied volatility, OI = open interest (contracts). Each contract covers 100 shares. Quotes delayed at least 15 minutes.
Frequently asked questions
What is the STRO put/call ratio?
For the October 16, 2026 expiration, the STRO put/call ratio based on open interest is 0.01 (12 puts vs 977 calls), and 0.80 based on today's volume. A ratio above 1 means more puts than calls.
What is STRO's implied volatility?
At-the-money implied volatility for STRO options expiring October 16, 2026 is about 215.4%, an annualized estimate of how much the market expects Sutro Biopharma stock to move.
How many STRO option expiration dates are there?
STRO has 4 listed expiration dates, from Oct 16, 2026 to May 21, 2027.
What does "in the money" mean?
A call is in the money when the strike price is below the current share price; a put is in the money when the strike is above it. In-the-money contracts have intrinsic value and are shaded in the table.