About Atara Biotherapeutics, Inc. (ATRA) data
Data as of August 14, 2026.
Atara Biotherapeutics, Inc. (ATRA) has 477.27K shares sold short as of the latest FINRA settlement report on August 14, 2026. Short interest has decreased by 11.11% compared with the prior settlement. At the current average daily volume, covering all open short positions would take about 9.21 days (days to cover).
Recent ATRA short interest history
| Settlement date | Short interest | Change | Days to cover |
|---|---|---|---|
| Aug 14, 2026 | 477,268 | -11.11% | 9.21 |
| Jul 31, 2026 | 536,897 | -7.05% | 9.39 |
| Jul 15, 2026 | 577,635 | 59.78% | 6.24 |
| Jun 30, 2026 | 361,520 | -26.58% | 3.95 |
| Jun 15, 2026 | 492,405 | 1.65% | 6.27 |
| May 29, 2026 | 484,391 | -11.36% | 2.91 |
| May 15, 2026 | 546,470 | 78.53% | 1.00 |
| Apr 30, 2026 | 306,093 | -3.73% | 6.10 |
| Apr 15, 2026 | 317,953 | -2.79% | 4.10 |
| Mar 31, 2026 | 327,066 | 4.40% | 3.01 |
| Mar 13, 2026 | 313,290 | -5.21% | 1.00 |
| Feb 27, 2026 | 330,524 | 57.93% | 2.13 |
Full history, charts, and borrow-fee detail are on the ATRA short interest page.
Frequently asked questions
What is the current short interest in ATRA?
As of the latest FINRA settlement dated August 14, 2026, ATRA had approximately 477,268 shares sold short. Short interest data is reported by FINRA twice per month.
How much does it cost to short ATRA?
The latest borrow fee (cost to borrow) for ATRA is 5.48% per year, based on IBKR data. Fees can change throughout the trading day as shares are borrowed and returned.
What is the days to cover ratio for ATRA?
Days to cover for ATRA is approximately 9.21 days. This estimates how many trading days it would take short sellers to buy back all outstanding short shares at the current average daily volume.
Is ATRA a short squeeze candidate?
A squeeze needs shorts that are hard to close. ATRA trades about 51,842 shares a day and would take roughly 9.21 days to unwind current short positions, at a current borrow fee of 5.48%. Higher days-to-cover and a rising borrow fee together are the setup to watch; neither alone is enough.