ZBIO Short Interest (September 15, 2026 Update)
Short interest for ZBIO was 11.9M as of September 15, 2026, +1.4% from the prior report.
This page tracks ZBIO short interest over time, including historical values, changes between reports, and days to cover.
Zenas BioPharma, Inc. Common S | ZBIO | Nasdaq | Latest report: September 15, 2026
At the latest settlement date of September 15, 2026, Zenas BioPharma, Inc. Common S (ZBIO) showed reported short interest of 11,871,346 shares. That compared with 11,702,288 shares in the prior report, a change of 169.1K shares, or +1.4%. The latest reported days to cover was 22.43, based on average daily volume of 529.3K.
The historical data currently tracked for ZBIO includes 46 reported entries from September 30, 2024 to September 15, 2026. Over that span, reported short interest has ranged from 230.6K to 12.2M 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 |
|---|---|---|---|---|---|---|
| September 15, 2026 | 11,871,346 | 11,702,288 | 169.1K | +1.4% | 529.3K | 22.43 |
| August 31, 2026 | 11,702,288 | 11,658,986 | 43.3K | +0.4% | 825.0K | 14.18 |
| August 14, 2026 | 11,658,986 | 11,753,566 | -94.6K | -0.8% | 553.7K | 21.06 |
| July 31, 2026 | 11,753,566 | 12,169,907 | -416.3K | -3.4% | 850.1K | 13.83 |
| July 15, 2026 | 12,169,907 | 12,196,436 | -26.5K | -0.2% | 976.9K | 12.46 |
| June 30, 2026 | 12,196,436 | 11,131,739 | 1.1M | +9.6% | 1.3M | 9.64 |
| June 15, 2026 | 11,131,739 | 10,879,470 | 252.3K | +2.3% | 575.8K | 19.33 |
| May 29, 2026 | 10,879,470 | 10,687,286 | 192.2K | +1.8% | 599.9K | 18.13 |
| May 15, 2026 | 10,687,286 | 10,853,674 | -166.4K | -1.5% | 501.4K | 21.31 |
| April 30, 2026 | 10,853,674 | 10,223,630 | 630.0K | +6.2% | 452.8K | 23.97 |
| April 15, 2026 | 10,223,630 | 9,362,107 | 861.5K | +9.2% | 826.4K | 12.37 |
| March 31, 2026 | 9,362,107 | 7,709,823 | 1.7M | +21.4% | 1.3M | 7.48 |
| March 13, 2026 | 7,709,823 | 8,023,712 | -313.9K | -3.9% | 346.6K | 22.25 |
| 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 | -0.5% | 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 |