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Stock research / United States / QSI / Short interest

Quantum-Si Inc. short interest

13.2M shares of Quantum-Si were sold short at the 15 October 2026 settlement, near the bottom of its range over the last year (11.8M to 23.3M). Short sellers would need 1.0 days of normal trading to buy them back.

Shares sold short13.2Mat 15 Oct 2026
Change on the settlement before+11.6%-34% over a year
Days to cover1.00at 14.9M shares a day
Of shares in issue6.03%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 bottom of its range over the last year (11.8M to 23.3M), and the share price moved -45% 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

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    Every settlement since 15 Jun 2021 as a table
    SettlementShares shortChangeAverage daily volumeDays to cover
    15 October 202613.2M+11.6%14.9M1.00
    30 September 202611.8M-9.3%4.8M2.46
    15 September 202613.0M-9.7%1.3M10.32
    31 August 202614.4M+1.2%3.0M4.78
    14 August 202614.3M-7.4%3.0M4.68
    31 July 202615.4M+9.1%2.6M5.91
    15 July 202614.1M-18.8%3.3M4.24
    30 June 202617.4M-22.7%6.4M2.72
    15 June 202622.5M-1.3%6.6M3.40
    29 May 202622.8M-1.9%7.0M3.25
    15 May 202623.3M+1.2%6.0M3.88
    30 April 202623.0M+0.1%6.8M3.40
    15 April 202622.9M+3.6%4.1M5.57
    31 March 202622.1M+2.9%3.1M7.21
    13 March 202621.5M+1.8%4.1M5.19
    27 February 202621.1M-1.0%2.6M8.03
    13 February 202621.3M+13.2%5.0M4.23
    30 January 202618.9M-2.4%4.8M3.91
    15 January 202619.3M+0.3%5.3M3.65
    31 December 202519.3M-0.3%5.3M3.63
    15 December 202519.3M+2.6%4.1M4.74
    28 November 202518.8M+19.3%4.7M3.98
    14 November 202515.8M-6.9%7.4M2.13
    31 October 202517.0M-15.0%15.7M1.08
    15 October 202519.9M-9.1%19.6M1.02
    30 September 202521.9M-0.2%15.5M1.41
    15 September 202522.0M-2.0%5.0M4.44
    29 August 202522.4M-4.3%6.0M3.71
    15 August 202523.4M+7.5%7.0M3.35
    31 July 202521.8M-7.0%7.5M2.92
    15 July 202523.5M-2.3%8.3M2.83
    30 June 202524.0M+0.7%9.1M2.63
    13 June 202523.8M-1.3%6.8M3.50
    30 May 202524.2M+2.8%16.6M1.45
    15 May 202523.5M+2.7%5.3M4.41
    30 April 202522.9M-0.2%2.5M9.19
    15 April 202522.9M+11.5%3.5M6.50
    31 March 202520.6M+23.6%10.5M1.96
    14 March 202516.6M-5.8%6.9M2.41
    28 February 202517.7M-6.0%7.7M2.29
    14 February 202518.8M+0.4%10.0M1.88
    31 January 202518.7M+0.8%15.8M1.18
    15 January 202518.6M-21.4%66.0M1.00
    31 December 202423.6M+109.8%54.4M1.00
    13 December 202411.3M+24.0%17.1M1.00
    29 November 20249.1M+76.8%42.8M1.00
    15 November 20245.1M-12.9%727K7.07
    31 October 20245.9M-0.1%566K10.43
    15 October 20245.9M-3.2%346K17.05
    30 September 20246.1M+4.3%526K11.60
    13 September 20245.8M-2.4%364K16.07
    30 August 20246.0M+2.4%456K13.15
    15 August 20245.9M-6.5%652K8.98
    31 July 20246.3M-2.2%542K11.54
    15 July 20246.4M-7.4%730K8.77
    28 June 20246.9M-6.5%2.3M3.01
    14 June 20247.4M-0.0%420K17.58
    31 May 20247.4M+5.4%474K15.60
    15 May 20247.0M-8.9%636K11.03
    30 April 20247.7M+4.0%508K15.16
    15 April 20247.4M-1.9%568K13.03
    28 March 20247.5M+2.5%751K10.05
    15 March 20247.4M-5.9%1.4M5.13
    29 February 20247.8M-5.1%564K13.87
    15 February 20248.2M+5.6%643K12.83
    31 January 20247.8M-18.3%543K14.39
    12 January 20249.6M+7.2%631K15.15
    29 December 20238.9M+10.4%867K10.29
    15 December 20238.1M-18.5%670K12.06
    30 November 20239.9M+7.9%578K17.14
    15 November 20239.2M+2.1%884K10.38
    31 October 20239.0M-5.2%666K13.49
    13 October 20239.5M-1.6%653K14.51
    29 September 20239.6M-6.2%805K11.97
    15 September 202310.3M+23.1%1.0M9.93
    31 August 20238.3M-1.1%1.4M5.75
    15 August 20238.4M+53.5%3.4M2.47
    31 July 20235.5M+34.8%4.4M1.24
    14 July 20234.1M+12.9%1.6M2.54
    30 June 20233.6M+11.5%1.4M2.60
    15 June 20233.2M-1.3%468K6.91
    31 May 20233.3M-2.0%430K7.63
    15 May 20233.3M-1.1%393K8.53
    28 April 20233.4M+1.1%414K8.18
    14 April 20233.4M-3.3%743K4.51
    31 March 20233.5M+4.4%693K5.00
    15 March 20233.3M+5.9%845K3.93
    28 February 20233.1M+9.2%775K4.04
    15 February 20232.9M-6.6%623K4.61
    31 January 20233.1M-12.2%523K5.87
    13 January 20233.5M-5.5%704K4.97
    30 December 20223.7M+2.1%996K3.72
    15 December 20223.6M-14.7%588K6.17
    30 November 20224.3M-0.4%831K5.12
    15 November 20224.3M+6.0%905K4.72
    31 October 20224.0M-4.0%473K8.52
    14 October 20224.2M+0.9%602K6.97
    30 September 20224.2M-4.3%452K9.20
    15 September 20224.3M-0.8%342K12.70
    31 August 20224.4M-5.3%354K12.37
    15 August 20224.6M+1.2%694K6.67
    29 July 20224.6M-16.8%550K8.32
    15 July 20225.5M-3.3%818K6.71
    30 June 20225.7M+9.4%3.1M1.81
    15 June 20225.2M-10.1%742K7.01
    31 May 20225.8M-2.8%645K8.96
    13 May 20225.9M+9.2%852K6.98
    29 April 20225.4M-2.5%721K7.55
    14 April 20225.6M-5.3%680K8.21
    31 March 20225.9M+3.0%1.1M5.46
    15 March 20225.7M-6.5%1.1M5.31
    28 February 20226.1M+20.7%1.5M3.97
    15 February 20225.1M-14.6%1.0M4.84
    31 January 20225.9M+6.5%1.5M3.97
    14 January 20225.6M+11.9%927K6.03
    31 December 20215.0M-7.7%1.6M3.18
    15 December 20215.4M+6.3%824K6.57
    30 November 20215.1M+2.5%974K5.23
    15 November 20215.0M-2.4%630K7.88
    29 October 20215.1M-3.6%666K7.63
    15 October 20215.3M+7.9%522K10.10
    30 September 20214.9M+34.3%1.1M4.63
    15 September 20213.6M-5.1%756K4.82
    31 August 20213.8M+16.5%1.1M3.39
    13 August 20213.3M-18.5%1.6M2.00
    30 July 20214.0M-2.4%1.7M2.33
    15 July 20214.1M+72.1%1.3M3.26
    30 June 20212.4M+71.5%1.6M1.50
    15 June 20211.4M612K2.29
    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.