Sutro Biopharma (STRO) Short Interest
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%
Latest short interest · Sep 15, 2026
- Shares short
- 2.08M
- Change vs prior
- +14.7%
- Short % of shares out.
- 12.52%
- Days to cover
- 5.99
- Avg. daily volume
- 346.61K
- Prior report
- 1.81M
Sutro Biopharma short interest analysis
As of the Sep 15, 2026 settlement date, 2,076,152 STRO shares were sold short, equal to 12.52% of Sutro Biopharma's shares outstanding. That is up 14.7% from the previous report of 1.81M shares. With average daily volume of 346.61K shares, it would take about 6.0 trading days for short sellers to buy back their positions, which is elevated by typical standards.
The latest reading is the highest in the 12 reports shown.
Summary generated from market data by MetaCap's automated system. Methodology
STRO short interest history
| Settlement | Short Interest | Change | % Shares Out. | Days to Cover |
|---|---|---|---|---|
| Sep 15, 2026 | 2,076,152 | +14.7% | 12.52% | 5.99 |
| Aug 31, 2026 | 1,809,482 | -2.5% | 10.91% | 8.53 |
| Aug 14, 2026 | 1,855,694 | +6.3% | 11.19% | 5.39 |
| Jul 31, 2026 | 1,744,843 | +5.6% | 10.52% | 6.35 |
| Jul 15, 2026 | 1,652,824 | +21.4% | 9.97% | 4.46 |
| Jun 30, 2026 | 1,361,955 | +47.7% | 8.21% | 2.31 |
| Jun 15, 2026 | 922,188 | +22.7% | 5.56% | 3.90 |
| May 29, 2026 | 751,365 | -37.0% | 4.53% | 1.73 |
| May 15, 2026 | 1,193,156 | +22.1% | 7.20% | 5.61 |
| Apr 30, 2026 | 977,108 | +30.5% | 5.89% | 3.91 |
| Apr 15, 2026 | 748,699 | +17.0% | 4.52% | 2.88 |
| Mar 31, 2026 | 639,714 | +20.1% | 3.86% | 2.79 |
Days to cover = shares short ÷ average daily volume. Short percent uses total shares outstanding as the denominator, which is slightly lower than a float-based figure.
Frequently asked questions
What is Sutro Biopharma's short interest?
STRO short interest was 2,076,152 shares as of Sep 15, 2026, or 12.52% of shares outstanding, up 14.7% from the prior report.
What is STRO's days to cover?
STRO's days-to-cover (short interest ratio) is 5.99, meaning short sellers would need about 6.0 days of average trading volume to close their positions.
How often is short interest reported?
FINRA requires brokers to report short positions twice a month, as of mid-month and month-end settlement dates. The data is published about a week and a half after each settlement date, so it is always somewhat delayed.
Is high short interest bullish or bearish?
High short interest shows that many investors expect the price to fall, which is a bearish signal. It can also set up a short squeeze if the stock rises and short sellers rush to buy back shares. Neither outcome is guaranteed.