greeksoup/ stock research
Stock research / United States / CERS / Short interest

Cerus Corp. short interest

16.6M shares of Cerus were sold short at the 15 October 2026 settlement, near the top of its range over the last year (5.2M to 19.7M). Short sellers would need 9.4 days of normal trading to buy them back.

Shares sold short16.6Mat 15 Oct 2026
Change on the settlement before-5.4%+221% over a year
Days to cover9.39at 1.8M shares a day
Of shares in issue8.25%shares short over shares outstanding
New to this? How to read this page
  1. Short interest is the number of shares investors have borrowed and sold, betting the price will fall, and not yet bought back.
  2. Days to cover is shares short over an average day's trading: how many days it would take short sellers to buy them all back. Above 5 or so is high.
  3. Rising short interest says more investors are betting against the stock. A crowded short can also rise fast if shorts rush to buy back.
  4. Brokers report it twice a month to FINRA, about ten days after each settlement date.
  5. What is short interest?

Short interest, days to cover and the price

Short interest is near the top of its range over the last year (5.2M to 19.7M), and the share price moved +53% over the last year.

Shares sold shortDays to coverShare price

Three charts on one timeline. Top: shares sold short at each settlement. Middle: days to cover, taller meaning shorts would need longer to buy back. Bottom: the share price, so you can see whether shorts added as the price fell or rose.

How it compares

every company on the site

    The bar ranks every company on the site from the lowest on the left to the highest on the right, in three equal thirds; the small figures under it are the values where each third starts, and the black tick is the middle company. The orange dot is this company; the grey ticks are the other companies in its industry (hover or tap for names). A hatched block is companies tied at none.

    Every settlement since 29 Dec 2017 as a table
    SettlementShares shortChangeAverage daily volumeDays to cover
    15 October 202616.6M-5.4%1.8M9.39
    30 September 202617.6M-2.3%2.2M8.03
    15 September 202618.0M+1.6%1.1M16.58
    31 August 202617.7M+2.2%1.8M10.02
    14 August 202617.3M+15.8%3.4M5.07
    31 July 202615.0M+9.3%2.6M5.71
    15 July 202613.7M+7.5%2.5M5.50
    30 June 202612.7M-35.3%3.1M4.14
    15 June 202619.7M+82.9%2.3M8.49
    29 May 202610.8M-41.9%2.5M4.24
    15 May 202618.5M+64.3%4.6M4.00
    30 April 202611.3M+0.6%1.1M10.51
    15 April 202611.2M+0.8%900K12.45
    31 March 202611.1M+5.8%1.8M6.30
    13 March 202610.5M+35.1%2.9M3.61
    27 February 20267.8M-0.5%1.4M5.69
    13 February 20267.8M+16.3%977K8.01
    30 January 20266.7M-5.9%1.1M5.93
    15 January 20267.1M+6.4%2.0M3.62
    31 December 20256.7M+7.6%1.4M4.85
    15 December 20256.2M+6.9%1.7M3.60
    28 November 20255.8M+2.1%1.3M4.46
    14 November 20255.7M+9.5%1.4M4.11
    31 October 20255.2M+1.0%1.1M4.72
    15 October 20255.2M-16.5%1.3M3.90
    30 September 20256.2M-43.8%1.8M3.37
    15 September 202511.0M+59.6%1.2M8.89
    29 August 20256.9M-29.1%1.0M6.88
    15 August 20259.7M+39.0%1.4M6.94
    31 July 20257.0M-5.1%921K7.61
    15 July 20257.4M-7.3%890K8.30
    30 June 20258.0M+18.6%1.2M6.46
    13 June 20256.7M-25.7%1.6M4.19
    30 May 20259.0M+2.3%1.3M7.18
    15 May 20258.8M-5.9%1.1M8.33
    30 April 20259.4M-10.5%903K10.40
    15 April 202510.5M+6.1%1.5M7.02
    31 March 20259.9M-3.4%1.5M6.67
    14 March 202510.2M+1.4%1.6M6.32
    28 February 202510.1M+8.4%1.3M7.58
    14 February 20259.3M+8.2%1.0M9.01
    31 January 20258.6M-1.3%1.8M4.76
    15 January 20258.7M+11.7%1.6M5.43
    31 December 20247.8M+16.3%1.4M5.72
    13 December 20246.7M+1.3%1.1M6.33
    29 November 20246.6M-4.3%920K7.20
    15 November 20246.9M-12.7%1.9M3.63
    31 October 20247.9M+7.9%2.4M3.31
    15 October 20247.4M+4.5%1.4M5.23
    30 September 20247.0M+6.1%1.1M6.66
    13 September 20246.6M+3.5%645K10.29
    30 August 20246.4M+0.4%673K9.52
    15 August 20246.4M-0.5%1.1M5.63
    31 July 20246.4M-6.0%966K6.64
    15 July 20246.8M-4.4%1.1M6.44
    28 June 20247.1M+7.7%854K8.36
    14 June 20246.6M+3.3%648K10.24
    31 May 20246.4M+6.7%778K8.25
    15 May 20246.0M+5.2%1.4M4.18
    30 April 20245.7M-3.4%779K7.34
    15 April 20245.9M+0.6%1.0M5.70
    28 March 20245.9M+16.0%3.7M1.58
    15 March 20245.1M+12.7%1.8M2.75
    29 February 20244.5M+4.1%860K5.23
    15 February 20244.3M-3.5%1.3M3.30
    31 January 20244.5M+5.8%1.3M3.48
    12 January 20244.2M-8.0%1.1M3.92
    29 December 20234.6M-13.2%1.3M3.49
    15 December 20235.3M-5.0%1.9M2.73
    30 November 20235.6M-7.8%1.5M3.64
    15 November 20236.1M-3.0%1.3M4.54
    31 October 20236.2M+11.5%885K7.05
    13 October 20235.6M-3.9%1.0M5.36
    29 September 20235.8M+8.5%1.2M5.02
    15 September 20235.4M-4.0%1.2M4.42
    31 August 20235.6M-4.6%929K6.01
    15 August 20235.9M+7.7%1.4M4.28
    31 July 20235.4M-1.7%956K5.68
    14 July 20235.5M-9.2%1.4M3.94
    30 June 20236.1M-0.5%1.2M5.02
    15 June 20236.1M-5.0%1.3M4.61
    31 May 20236.4M-11.9%1.6M3.99
    15 May 20237.3M-0.1%1.3M5.60
    28 April 20237.3M-7.9%870K8.40
    14 April 20237.9M-5.6%922K8.61
    31 March 20238.4M-5.2%1.6M5.23
    15 March 20238.9M+15.6%2.3M3.79
    28 February 20237.7M+17.3%1.4M5.58
    15 February 20236.5M+4.6%1.3M5.05
    31 January 20236.3M-0.3%1.4M4.49
    13 January 20236.3M+11.7%2.0M3.16
    30 December 20225.6M+0.2%1.3M4.46
    15 December 20225.6M-9.8%1.2M4.56
    30 November 20226.2M+0.2%855K7.28
    15 November 20226.2M-6.5%1.3M4.83
    31 October 20226.6M-6.9%946K7.02
    14 October 20227.1M-5.9%1.3M5.46
    30 September 20227.6M+10.0%1.4M5.32
    15 September 20226.9M-2.3%1.7M4.08
    31 August 20227.1M+20.5%1.7M4.21
    15 August 20225.9M+0.1%1.7M3.46
    29 July 20225.8M-12.7%1.3M4.58
    15 July 20226.7M-5.2%1.6M4.17
    30 June 20227.1M-9.7%1.7M4.06
    15 June 20227.8M+7.8%1.7M4.73
    31 May 20227.3M-5.2%3.1M2.35
    13 May 20227.7M-13.4%3.2M2.43
    29 April 20228.8M+5.2%1.8M4.83
    14 April 20228.4M+3.0%1.1M7.78
    31 March 20228.2M-3.0%1.3M6.09
    15 March 20228.4M-3.5%1.5M5.56
    28 February 20228.7M-2.1%1.7M5.25
    15 February 20228.9M+4.0%1.5M6.06
    31 January 20228.6M+5.0%2.3M3.70
    14 January 20228.2M-3.7%1.6M5.19
    31 December 20218.5M-6.5%1.5M5.52
    15 December 20219.1M+1.6%1.6M5.74
    30 November 20218.9M-4.6%1.3M7.08
    15 November 20219.4M-19.1%1.8M5.07
    29 October 202111.6M+6.8%711K16.26
    15 October 202110.8M+2.3%843K12.85
    30 September 202110.6M-5.5%1.2M8.89
    15 September 202111.2M-3.0%745K15.02
    31 August 202111.5M-22.5%1.1M10.73
    13 August 202114.9M+16.7%2.3M6.52
    30 July 202112.8M-1.3%1.1M11.60
    15 July 202112.9M-1.5%1.8M7.25
    30 June 202113.1M-16.9%1.8M7.28
    15 June 202115.8M+14.9%1.4M11.52
    28 May 202113.8M+0.1%1.5M9.10
    14 May 202113.7M+8.8%2.2M6.35
    30 April 202112.6M-1.4%1.3M9.48
    15 April 202112.8M-13.4%1.5M8.52
    31 March 202114.8M+6.8%2.3M6.30
    15 March 202113.8M+50.0%3.2M4.33
    26 February 20219.2M+0.4%1.9M4.85
    12 February 20219.2M+0.9%1.7M5.44
    29 January 20219.1M+5.8%1.4M6.52
    15 January 20218.6M+1.6%1.7M5.10
    31 December 20208.5M-19.5%2.5M3.32
    15 December 202010.5M+2.8%2.2M4.73
    30 November 202010.2M+7.2%1.4M7.31
    13 November 20209.5M-9.1%1.3M7.35
    30 October 202010.5M+5.6%1.2M8.99
    15 October 20209.9M-7.6%1.4M7.30
    30 September 202010.7M-1.8%1.1M9.50
    15 September 202010.9M-4.3%1.4M8.05
    31 August 202011.4M+15.2%1.6M7.00
    14 August 20209.9M+0.3%1.3M7.79
    31 July 20209.9M-6.9%1.5M6.62
    15 July 202010.6M+1.2%1.8M6.00
    30 June 202010.5M+16.0%2.2M4.69
    15 June 20209.0M+9.4%2.1M4.30
    29 May 20208.3M-4.3%1.6M5.18
    15 May 20208.6M-7.0%2.0M4.27
    30 April 20209.3M-0.4%1.6M5.99
    15 April 20209.3M+2.5%1.5M6.35
    31 March 20209.1M-6.6%2.1M4.39
    13 March 20209.7M+9.7%1.6M5.98
    28 February 20208.9M-6.7%2.4M3.63
    14 February 20209.5M+2.9%2.0M4.72
    31 January 20209.2M-7.5%2.0M4.57
    15 January 202010.0M+0.8%876K11.41
    31 December 20199.9M+4.2%789K12.56
    13 December 20199.5M+13.8%753K12.64
    29 November 20198.4M+0.5%884K9.47
    15 November 20198.3M+6.5%1.1M7.82
    31 October 20197.8M+5.2%786K9.94
    15 October 20197.4M+4.7%969K7.66
    30 September 20197.1M-5.5%876K8.09
    13 September 20197.5M+7.3%741K10.14
    30 August 20197.0M+20.9%793K8.83
    15 August 20195.8M+6.2%916K6.32
    31 July 20195.5M-10.8%900K6.06
    15 July 20196.1M+28.2%683K8.96
    28 June 20194.8M+5.7%1.4M3.35
    14 June 20194.5M-13.3%1.3M3.53
    31 May 20195.2M-10.0%850K6.12
    15 May 20195.8M+23.5%1.5M3.94
    30 April 20194.7M+11.5%528K8.87
    15 April 20194.2M+4.7%514K8.16
    29 March 20194.0M+10.4%634K6.33
    15 March 20193.6M+2.7%741K4.90
    28 February 20193.5M-7.9%1.2M3.07
    15 February 20193.8M+2.5%588K6.53
    31 January 20193.7M-0.1%656K5.72
    15 January 20193.8M+1.9%729K5.15
    31 December 20183.7M+12.5%1.1M3.45
    14 December 20183.3M+11.9%1.1M2.93
    30 November 20182.9M-7.0%606K4.82
    15 November 20183.1M+51.7%1.2M2.57
    31 October 20182.1M+13.3%1.0M2.04
    15 October 20181.8M-2.1%767K2.39
    28 September 20181.9M+24.8%633K2.95
    14 September 20181.5M+11.1%661K2.27
    31 August 20181.3M-17.3%945K1.43
    15 August 20181.6M-2.7%946K1.72
    31 July 20181.7M-12.5%705K2.38
    13 July 20181.9M-11.3%758K2.53
    29 June 20182.2M-23.6%1.4M1.51
    15 June 20182.8M-10.0%883K3.20
    31 May 20183.1M-19.1%973K3.22
    15 May 20183.9M-12.5%1.3M3.00
    30 April 20184.4M-2.2%663K6.69
    13 April 20184.5M-9.2%877K5.16
    29 March 20185.0M+0.8%1.6M3.04
    15 March 20184.9M-4.7%1.5M3.40
    28 February 20185.2M-0.1%629K8.26
    15 February 20185.2M-35.4%1.3M3.86
    31 January 20188.1M+9.4%3.1M2.63
    12 January 20187.4M-6.0%884K8.32
    29 December 20177.8M572K13.69
    Shares in millions (M) or thousands (K); hold the pointer on a figure for the exact count. FINRA publishes consolidated short interest twice a month, about ten days after each settlement.