aTyr Pharma, Inc. Common Stock | ATYR | Nasdaq | Latest report: February 27, 2026
aTyr Pharma, Inc. Common Stock (ATYR) reported short interest of 18,802,360 shares for the settlement date of February 27, 2026. The prior report showed 19,877,366 shares. That was a change of -1.1M shares, while the latest days-to-cover reading came in at 11.6 using reported average daily volume of 1.6M.
ShortInterestHistory.com currently tracks 40 report entries for ATYR, covering the period from June 14, 2024 through February 27, 2026. Reported short interest during that stretch ranged from 270.6K to 36.1M shares.
Extreme edge-case readings may reflect unusually low reported average volume.
| Settlement Date | Short Interest | Prior Short Interest | Change Shares | Change % | Average Daily Volume | Days to Cover |
|---|---|---|---|---|---|---|
| February 27, 2026 | 18,802,360 | 19,877,366 | -1.1M | -5.4% | 1.6M | 11.6 |
| February 13, 2026 | 19,877,366 | 20,432,971 | -555.6K | -2.7% | 2.4M | 8.42 |
| January 30, 2026 | 20,432,971 | 21,334,051 | -901.1K | -4.2% | 2.6M | 7.72 |
| January 15, 2026 | 21,334,051 | 25,013,857 | -3.7M | -14.7% | 1.5M | 14.17 |
| December 31, 2025 | 25,013,857 | 30,385,566 | -5.4M | -17.7% | 2.2M | 11.13 |
| December 15, 2025 | 30,385,566 | 29,801,092 | 584.5K | +2.0% | 2.0M | 15.47 |
| November 28, 2025 | 29,801,092 | 29,864,642 | -63.5K | -0.2% | 3.2M | 9.24 |
| November 14, 2025 | 29,864,642 | 31,060,738 | -1.2M | -3.9% | 3.9M | 7.62 |
| October 31, 2025 | 31,060,738 | 36,142,593 | -5.1M | -14.1% | 5.1M | 6.08 |
| October 15, 2025 | 36,142,593 | 37,932,369 | -1.8M | -4.7% | 10.7M | 3.39 |
| September 15, 2025 | 33,089,093 | 29,405,110 | 3.7M | +12.5% | 21.0M | 1.58 |
| August 29, 2025 | 29,405,110 | 28,245,132 | 1.2M | +4.1% | 3.7M | 8.04 |
| August 15, 2025 | 28,245,132 | 25,598,382 | 2.6M | +10.3% | 3.9M | 7.17 |
| July 31, 2025 | 25,598,382 | 20,381,870 | 5.2M | +25.6% | 7.5M | 3.42 |
| July 15, 2025 | 20,381,870 | 18,464,705 | 1.9M | +10.4% | 3.5M | 5.82 |
| June 30, 2025 | 18,464,705 | 13,644,953 | 4.8M | +35.3% | 4.2M | 4.4 |
| June 13, 2025 | 13,644,953 | 13,770,149 | -125.2K | -0.9% | 2.9M | 4.65 |
| May 30, 2025 | 13,770,149 | 12,681,301 | 1.1M | +8.6% | 1.7M | 8.24 |
| May 15, 2025 | 12,681,301 | 11,691,227 | 990.1K | +8.5% | 1.2M | 10.42 |
| April 30, 2025 | 11,691,227 | 10,025,170 | 1.7M | +16.6% | 1.1M | 10.96 |
| April 15, 2025 | 10,025,170 | 8,322,026 | 1.7M | +20.5% | 1.5M | 6.64 |
| March 31, 2025 | 8,322,026 | 6,920,509 | 1.4M | +20.2% | 1.3M | 6.35 |
| February 28, 2025 | 5,259,028 | 4,354,940 | 904.1K | +20.8% | 2.0M | 2.58 |
| February 14, 2025 | 4,354,940 | 3,816,730 | 538.2K | +14.1% | 818.4K | 5.32 |
| January 31, 2025 | 3,816,730 | 3,515,857 | 300.9K | +8.6% | 641.7K | 5.95 |
| January 15, 2025 | 3,515,857 | 3,647,026 | -131.2K | -3.6% | 990.1K | 3.55 |
| December 31, 2024 | 3,647,026 | 2,920,070 | 727.0K | +24.9% | 958.8K | 3.8 |
| December 13, 2024 | 2,920,070 | 2,173,825 | 746.2K | +34.3% | 674.7K | 4.33 |
| November 29, 2024 | 2,173,825 | 2,114,376 | 59.4K | +2.8% | 793.0K | 2.74 |
| November 15, 2024 | 2,114,376 | 1,662,000 | 452.4K | +27.2% | 806.1K | 2.62 |
| October 31, 2024 | 1,662,000 | 1,065,364 | 596.6K | +56.0% | 1.3M | 1.24 |
| October 15, 2024 | 1,065,364 | 1,364,879 | -299.5K | -21.9% | 1.5M | 1 |
| September 30, 2024 | 1,364,879 | 685,779 | 679.1K | +99.0% | 314.3K | 4.34 |
| September 13, 2024 | 685,779 | 440,872 | 244.9K | +55.5% | 375.0K | 1.83 |
| August 30, 2024 | 440,872 | 346,758 | 94.1K | +27.1% | 259.9K | 1.7 |
| August 15, 2024 | 346,758 | 270,552 | 76.2K | +28.2% | 321.6K | 1.08 |
| July 31, 2024 | 270,552 | 336,586 | -66.0K | -19.6% | 591.3K | 1 |
| July 15, 2024 | 336,586 | 392,479 | -55.9K | -14.2% | 209.7K | 1.6 |
| June 28, 2024 | 392,479 | 276,520 | 116.0K | +41.9% | 476.8K | 1 |
| June 14, 2024 | 276,520 | 351,203 | -74.7K | -21.3% | 363.3K | 1 |