Zenas BioPharma, Inc. Common S | ZBIO | Nasdaq | Latest report: February 27, 2026
At the latest settlement date of February 27, 2026, Zenas BioPharma, Inc. Common S (ZBIO) showed reported short interest of 8,023,712 shares. That compared with 7,801,280 shares in the prior report, a change of 222.4K shares, or +2.9%. The latest reported days to cover was 10.7, based on average daily volume of 749.5K.
ShortInterestHistory.com currently tracks 33 report entries for ZBIO, covering the period from September 30, 2024 through February 27, 2026. Reported short interest during that stretch ranged from 230.6K to 8.0M 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 | 8,023,712 | 7,801,280 | 222.4K | +2.9% | 749.5K | 10.7 |
| February 13, 2026 | 7,801,280 | 6,568,745 | 1.2M | +18.8% | 927.3K | 8.41 |
| January 30, 2026 | 6,568,745 | 6,086,840 | 481.9K | +7.9% | 580.2K | 11.32 |
| January 15, 2026 | 6,086,840 | 4,779,373 | 1.3M | +27.4% | 2.0M | 3.01 |
| December 31, 2025 | 4,779,373 | 4,950,866 | -171.5K | -3.5% | 401.6K | 11.9 |
| December 15, 2025 | 4,950,866 | 4,858,909 | 92.0K | +1.9% | 286.0K | 17.31 |
| November 28, 2025 | 4,858,909 | 4,607,781 | 251.1K | +5.5% | 338.4K | 14.36 |
| November 14, 2025 | 4,607,781 | 4,766,849 | -159.1K | -3.3% | 373.3K | 12.34 |
| October 31, 2025 | 4,766,849 | 4,336,248 | 430.6K | +9.9% | 702.4K | 6.79 |
| October 15, 2025 | 4,336,248 | 5,616,578 | -1.3M | -22.8% | 440.1K | 9.85 |
| September 15, 2025 | 5,551,112 | 5,760,485 | -209.4K | -3.6% | 310.4K | 17.89 |
| August 29, 2025 | 5,760,485 | 5,265,933 | 494.6K | +9.4% | 209.1K | 27.55 |
| August 15, 2025 | 5,265,933 | 5,225,303 | 40.6K | +0.8% | 117.7K | 44.74 |
| July 31, 2025 | 5,225,303 | 5,072,285 | 153.0K | +3.0% | 126.0K | 41.48 |
| July 15, 2025 | 5,072,285 | 5,100,082 | -27.8K | -0.6% | 202.6K | 25.03 |
| June 30, 2025 | 5,100,082 | 4,910,375 | 189.7K | +3.9% | 182.6K | 27.93 |
| June 13, 2025 | 4,910,375 | 4,856,506 | 53.9K | +1.1% | 264.5K | 18.56 |
| May 30, 2025 | 4,856,506 | 4,915,974 | -59.5K | -1.2% | 116.4K | 41.72 |
| May 15, 2025 | 4,915,974 | 4,868,705 | 47.3K | +1.0% | 145.6K | 33.77 |
| April 30, 2025 | 4,868,705 | 4,391,730 | 477.0K | +10.9% | 138.7K | 35.1 |
| April 15, 2025 | 4,391,730 | 3,829,081 | 562.6K | +14.7% | 281.0K | 15.63 |
| March 31, 2025 | 3,829,081 | 3,735,691 | 93.4K | +2.5% | 224.4K | 17.06 |
| February 28, 2025 | 3,413,513 | 3,467,374 | -53.9K | -1.6% | 122.9K | 27.79 |
| February 14, 2025 | 3,467,374 | 3,298,451 | 168.9K | +5.1% | 164.6K | 21.07 |
| January 31, 2025 | 3,298,451 | 3,337,191 | -38.7K | -1.2% | 233.4K | 14.13 |
| January 15, 2025 | 3,337,191 | 3,216,251 | 120.9K | +3.8% | 189.1K | 17.65 |
| December 31, 2024 | 3,216,251 | 2,130,663 | 1.1M | +51.0% | 624.0K | 5.15 |
| December 13, 2024 | 2,130,663 | 1,470,292 | 660.4K | +44.9% | 362.2K | 5.88 |
| November 29, 2024 | 1,470,292 | 799,397 | 670.9K | +83.9% | 406.5K | 3.62 |
| November 15, 2024 | 799,397 | 635,745 | 163.7K | +25.7% | 86.9K | 9.19 |
| October 31, 2024 | 635,745 | 408,904 | 226.8K | +55.5% | 160.0K | 3.97 |
| October 15, 2024 | 408,904 | 230,551 | 178.4K | +77.4% | 153.7K | 2.66 |
| September 30, 2024 | 230,551 | 0 | 230.6K | +100.0% | 134.3K | 1.72 |