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HowShorted

How shorted is Cerus Corporation? CERS

#832most shorted US stockof 3,805 ranked stocks, more shorted than 78%

8.93%
of shares outstanding reported short · settlement date 15 Sep 2026
vs previous report
+0.14
5 reports (~10 weeks)
+2.57
days to cover
16.58
Aggregate net short position time series for Cerus Corporation

Markers along the chart's base: ▲ results announced (an 8-K reporting results was filed) ▲ quarterly or annual report filed. Dates are SEC filing dates; hover a point to see events since the previous settlement.

Days to cover

FINRA's own figure: reported shares short divided by the stock's average daily trading volume, published alongside each settlement. It expresses the short position in days of typical trading rather than as a percentage of the company; the two can move differently.

Aggregate net short position time series for Cerus Corporation days to cover

Short interest around results

For each results announcement (an 8-K reporting results, by its SEC filing date), the FINRA settlement before it and the first one after. Settlements fall twice a month, so the two figures can sit up to a month apart and much else changes in between: this shows what was reported, not why.

Reported short interest before and after each results announcement
Results filedSettlement beforeSettlement afterChange
30 Jul 20266.83% 15 Jul 20267.42% 31 Jul 2026+0.59
30 Apr 20265.83% 15 Apr 20269.24% 15 May 2026+3.41
2 Mar 20264.05% 27 Feb 20265.47% 13 Mar 2026+1.42
12 Jan 20263.50% 31 Dec 20253.72% 15 Jan 2026+0.22
6 Nov 20252.72% 31 Oct 20252.98% 14 Nov 2025+0.26
5 Aug 20253.65% 31 Jul 20255.08% 15 Aug 2025+1.43
1 May 20254.91% 30 Apr 20254.62% 15 May 2025−0.29
20 Feb 20255.01% 14 Feb 20255.43% 28 Feb 2025+0.42

Fails to deliver

The SEC's fails-to-deliver figure for CERS: the aggregate net balance of shares that failed to be delivered at each settlement date, published by the SEC twice a month and shown here verbatim for the trailing window. A balance is not a daily flow, and a fail has many ordinary causes; the SEC says it cannot guarantee the accuracy of the data. See what fails to deliver are and the largest balances today.

Last balance on file
541
26 Aug 2026
Highest in window
60,000
16 Jan 2026
Days with a balance
26
Window
16 Sep 2025 to 14 Sep 2026
Aggregate net short position time series for Cerus Corporation fails to deliver

Source: U.S. Securities and Exchange Commission, fails-to-deliver data (public domain). Only settlement days with a positive balance appear; the largest balance in the window was 60K shares.

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Sector: Healthcare

History

Full reported short interest history
Settlement dateShort %Change
15 Sep 20268.93%+0.14
31 Aug 20268.79%+0.19
14 Aug 20268.60%+1.18
31 Jul 20267.42%+0.59
15 Jul 20266.83%+0.47
30 Jun 20266.36%−3.47
15 Jun 20269.83%+4.46
29 May 20265.37%−3.87
15 May 20269.24%+3.61
30 Apr 20265.63%−0.20
15 Apr 20265.83%+0.04
31 Mar 20265.79%+0.32
13 Mar 20265.47%+1.42
27 Feb 20264.05%−0.02
13 Feb 20264.07%+0.57
30 Jan 20263.50%−0.22
15 Jan 20263.72%+0.22
31 Dec 20253.50%+0.25
15 Dec 20253.25%+0.21
28 Nov 20253.04%+0.06
14 Nov 20252.98%+0.26
31 Oct 20252.72%+0.02
15 Oct 20252.70%−0.53
30 Sep 20253.23%−2.52
15 Sep 20255.75%+2.15
29 Aug 20253.60%−1.48
15 Aug 20255.08%+1.43
31 Jul 20253.65%−0.21
15 Jul 20253.86%−0.31
30 Jun 20254.17%+0.66
13 Jun 20253.51%−1.22
30 May 20254.73%+0.11
15 May 20254.62%−0.29
30 Apr 20254.91%−0.74
15 Apr 20255.65%+0.33
31 Mar 20255.32%−0.19
14 Mar 20255.51%+0.08
28 Feb 20255.43%+0.42
14 Feb 20255.01%+0.38
31 Jan 20254.63%−0.06
15 Jan 20254.69%+0.49
31 Dec 20244.20%+0.59
13 Dec 20243.61%+0.04
29 Nov 20243.57%−0.16
15 Nov 20243.73%−0.54
31 Oct 20244.27%+0.30
15 Oct 20243.97%+0.17
30 Sep 20243.80%+0.22
13 Sep 20243.58%+0.12
30 Aug 20243.46%+0.02
15 Aug 20243.44%−0.02
31 Jul 20243.46%−0.23
15 Jul 20243.69%−0.17
28 Jun 20243.86%+0.27
14 Jun 20243.59%+0.12
31 May 20243.47%+0.22
15 May 20243.25%+0.16
30 Apr 20243.09%−0.17
15 Apr 20243.26%+0.02
28 Mar 20243.24%+0.44
15 Mar 20242.80%+0.32
29 Feb 20242.48%+0.10
15 Feb 20242.38%−0.09
31 Jan 20242.47%+0.14
12 Jan 20242.33%−0.21
29 Dec 20232.54%−0.38
15 Dec 20232.92%−0.16
30 Nov 20233.08%−0.26
15 Nov 20233.34%−0.10
31 Oct 20233.44%+0.35
13 Oct 20233.09%−0.13
29 Sep 20233.22%+0.25
15 Sep 20232.97%−0.12
31 Aug 20233.09%−0.15
15 Aug 20233.24%+0.23
31 Jul 20233.01%−0.05
14 Jul 20233.06%−0.31
30 Jun 20233.37%−0.02
15 Jun 20233.39%−0.17
31 May 20233.56%−0.49
15 May 20234.05%0.00
28 Apr 20234.05%−0.42
14 Apr 20234.47%−0.27
31 Mar 20234.74%−0.26
15 Mar 20235.00%+0.68
28 Feb 20234.32%+0.64
15 Feb 20233.68%+0.15
31 Jan 20233.53%−0.01
13 Jan 20233.54%+0.37
30 Dec 20223.17%+0.01
15 Dec 20223.16%−0.35
30 Nov 20223.51%+0.01
15 Nov 20223.50%−0.24
31 Oct 20223.74%−0.29
14 Oct 20224.03%−0.25
30 Sep 20224.28%+0.39
15 Sep 20223.89%−0.09
31 Aug 20223.98%+0.67
15 Aug 20223.31%+0.01
29 Jul 20223.30%−0.49
15 Jul 20223.79%−0.20
30 Jun 20223.99%−0.43
15 Jun 20224.42%+0.32
31 May 20224.10%−0.23
13 May 20224.33%−0.67
29 Apr 20225.00%+0.16
14 Apr 20224.84%+0.14
31 Mar 20224.70%−0.15
15 Mar 20224.85%−0.17
28 Feb 20225.02%−0.11
15 Feb 20225.13%+0.16
31 Jan 20224.97%+0.23
14 Jan 20224.74%−0.18
31 Dec 20214.92%−0.34
15 Dec 20215.26%+0.08
30 Nov 20215.18%−0.25
15 Nov 20215.43%−1.28
29 Oct 20216.71%+0.40
15 Oct 20216.31%+0.14
30 Sep 20216.17%−0.35
15 Sep 20216.52%−0.20
31 Aug 20216.72%−1.96
13 Aug 20218.68%+1.24
30 Jul 20217.44%−0.12
15 Jul 20217.56%−0.11
30 Jun 20217.67%−1.56
15 Jun 20219.23%+1.20
28 May 20218.03%+0.01
14 May 20218.02%+0.65
30 Apr 20217.37%−0.23
15 Apr 20217.60%−1.18
31 Mar 20218.78%+0.56
15 Mar 20218.22%+2.74
26 Feb 20215.48%+0.02
12 Feb 20215.46%+0.02
29 Jan 20215.44%+0.29
15 Jan 20215.15%+0.09
31 Dec 20205.06%−1.23
15 Dec 20206.29%+0.18
30 Nov 20206.11%+0.41
13 Nov 20205.70%−0.57
30 Oct 20206.27%+0.29
15 Oct 20205.98%−0.49
30 Sep 20206.47%−0.11
15 Sep 20206.58%−0.30
31 Aug 20206.88%+0.91
14 Aug 20205.97%+0.02
31 Jul 20205.95%−0.52
15 Jul 20206.47%+0.07
30 Jun 20206.40%+0.89
15 Jun 20205.51%+0.47
29 May 20205.04%−0.23
15 May 20205.27%−0.40
30 Apr 20205.67%−0.08
15 Apr 20205.75%+0.14
31 Mar 20205.61%−0.39
13 Mar 20206.00%+0.52
28 Feb 20205.48%−0.39
14 Feb 20205.87%−0.63
31 Jan 20206.50%−0.53
15 Jan 20207.03%+0.05
31 Dec 20196.98%+0.28
13 Dec 20196.70%+0.81
29 Nov 20195.89%+0.03
15 Nov 20195.86%+0.36
31 Oct 20195.50%+0.21
15 Oct 20195.29%+0.24
30 Sep 20195.05%−0.30
13 Sep 20195.35%+0.36
30 Aug 20194.99%+0.86
15 Aug 20194.13%+0.24
31 Jul 20193.89%−0.55
15 Jul 20194.44%+0.98
28 Jun 20193.46%+0.18
14 Jun 20193.28%−0.50
31 May 20193.78%−0.42
15 May 20194.20%+0.80
30 Apr 20193.40%+0.31
15 Apr 20193.09%+0.13
29 Mar 20192.96%+0.28
15 Mar 20192.68%+0.07
28 Feb 20192.61%−0.22
15 Feb 20192.83%+0.07
31 Jan 20192.76%−0.01
15 Jan 20192.77%+0.06
31 Dec 20182.71%+0.30
14 Dec 20182.41%+0.26
30 Nov 20182.15%−0.17
15 Nov 20182.32%+0.79
31 Oct 20181.53%+0.16
15 Oct 20181.37%−0.03
28 Sep 20181.40%+0.28
14 Sep 20181.12%+0.11
31 Aug 20181.01%−0.21
15 Aug 20181.22%−0.03
31 Jul 20181.25%−0.22
13 Jul 20181.47%−0.18
29 Jun 20181.65%−0.51
15 Jun 20182.16%−0.24
31 May 20182.40%−0.57
15 May 20182.97%−0.42
30 Apr 20183.39%−0.58
13 Apr 20183.97%−0.40
29 Mar 20184.37%+0.03
15 Mar 20184.34%−0.21
28 Feb 20184.55%−0.01
15 Feb 20184.56%−2.50
31 Jan 20187.06%+0.61
12 Jan 20186.45%−0.41
29 Dec 20176.86%–

Newest first. Scroll inside the table for earlier dates, back to 29 Dec 2017.

Frequently asked questions

How shorted is Cerus Corporation right now?
8.93% of Cerus Corporation's (CERS) shares outstanding were reported short for settlement date 15 Sep 2026, per FINRA's consolidated short interest report. That makes it the 832nd most shorted US stock, out of 3,805 we rank.
What does this number include?
FINRA member firms must report their short positions in all US equities twice a month; FINRA consolidates them per security. We divide that official share count by the company's shares outstanding from its SEC filings. This is the regulatory figure, not a daily estimate.
Why does it only update twice a month?
US short interest is reported for settlement on the 15th and the last business day of each month, and FINRA publishes the consolidated figures about nine business days later. That cadence is set by regulation; no daily official figure exists.
Is this CERS's short float?
No. This is short interest as a percentage of shares outstanding, the count in the company's SEC filings. "Short float" divides the same FINRA short count by the public float, which excludes closely held shares, so it comes out higher for the same company. We publish no float estimates: the float is not a regulatory figure.
What is CERS's days to cover?
16.58 days for settlement date 15 Sep 2026: FINRA's own short interest ratio, the reported shares short divided by average daily trading volume. It is published in the same FINRA file and shown verbatim; we hold no volume data ourselves.
Which funds are short?
US public short interest is aggregate-only: individual short sellers are not named. Only some EU markets publish named positions.