ShortInterestHistory.com

SION Short Interest History

Sionna Therapeutics, Inc. Comm | SION | Nasdaq | Latest report: February 27, 2026

Current Short Interest3.4M
Prior Short Interest3.1M
Change Shares285.4K
Change %+9.3%
Average Daily Volume143.4K
Days to Cover23.36

At the latest settlement date of February 27, 2026, Sionna Therapeutics, Inc. Comm (SION) showed reported short interest of 3,350,255 shares. That compared with 3,064,857 shares in the prior report, a change of 285.4K shares, or +9.3%. The latest reported days to cover was 23.36, based on average daily volume of 143.4K.

The historical data currently tracked for SION includes 24 reported entries from February 14, 2025 to February 27, 2026. During that span, reported short interest ranged between 630.7K and 3.8M shares.

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Short Interest Over Time

Days to Cover Over Time

Extreme edge-case readings may reflect unusually low reported average volume.

Short Interest History for SION

Settlement DateShort InterestPrior Short InterestChange SharesChange %Average Daily VolumeDays to Cover
February 27, 20263,350,2553,064,857285.4K+9.3%143.4K23.36
February 13, 20263,064,8573,143,560-78.7K-2.5%407.2K7.53
January 30, 20263,143,5603,053,66789.9K+2.9%231.9K13.55
January 15, 20263,053,6673,258,091-204.4K-6.3%312.3K9.78
December 31, 20253,258,0912,876,610381.5K+13.3%384.5K8.47
December 15, 20252,876,6102,862,55714.1K+0.5%289.4K9.94
November 28, 20252,862,5572,973,430-110.9K-3.7%266.3K10.75
November 14, 20252,973,4302,965,7767.7K+0.3%194.7K15.27
October 31, 20252,965,7763,372,058-406.3K-12.1%364.6K8.13
October 15, 20253,372,0583,931,123-559.1K-14.2%299.6K11.25
September 15, 20253,771,8203,475,743296.1K+8.5%306.3K12.31
August 29, 20253,475,7433,600,368-124.6K-3.5%197.6K17.59
August 15, 20253,600,3683,679,050-78.7K-2.1%174.7K20.61
July 31, 20253,679,0503,530,059149.0K+4.2%144.9K25.39
July 15, 20253,530,0593,631,953-101.9K-2.8%159.5K22.13
June 30, 20253,631,9532,827,394804.6K+28.5%355.4K10.22
June 13, 20252,827,3942,871,885-44.5K-1.6%138.6K20.41
May 30, 20252,871,8852,587,312284.6K+11.0%117.8K24.39
May 15, 20252,587,3122,502,34185.0K+3.4%173.9K14.88
April 30, 20252,502,3412,291,588210.8K+9.2%108.1K23.14
April 15, 20252,291,5882,280,72010.9K+0.5%180.5K12.69
March 31, 20252,280,7201,739,754541.0K+31.1%272.2K8.38
February 28, 20251,329,000630,656698.3K+110.7%199.9K6.65
February 14, 2025630,6560630.7K+100.0%301.4K2.09

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