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Aspen Aerogels Inc. short interest

6.1M shares of Aspen Aerogels were sold short at the 15 October 2026 settlement, near the bottom of its range over the last year (6.1M to 9.7M). Short sellers would need 7.6 days of normal trading to buy them back.

Shares sold short6.1Mat 15 Oct 2026
Change on the settlement before+0.7%-28% over a year
Days to cover7.64at 804K shares a day
Of shares in issue7.41%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 (6.1M to 9.7M), and the share price moved -43% 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 29 Dec 2017 as a table
    SettlementShares shortChangeAverage daily volumeDays to cover
    15 October 20266.1M+0.7%804K7.64
    30 September 20266.1M-32.7%1.2M5.24
    15 September 20269.1M+7.9%651K13.93
    31 August 20268.4M+3.9%771K10.89
    14 August 20268.1M-8.6%2.5M3.22
    31 July 20268.8M+7.6%988K8.96
    15 July 20268.2M+15.8%978K8.41
    30 June 20267.1M-0.1%1.9M3.76
    15 June 20267.1M+0.3%1.2M5.78
    29 May 20267.1M-8.4%1.5M4.62
    15 May 20267.7M-3.3%2.5M3.12
    30 April 20268.0M+14.0%1.6M5.02
    15 April 20267.0M+12.6%1.3M5.26
    31 March 20266.2M-11.7%1.2M5.33
    13 March 20267.1M-5.3%1.6M4.47
    27 February 20267.4M+0.2%2.5M3.04
    13 February 20267.4M-2.2%1.2M6.34
    30 January 20267.6M-13.0%1.6M4.86
    15 January 20268.7M-4.6%1.6M5.51
    31 December 20259.2M+9.2%2.3M4.01
    15 December 20258.4M-2.2%1.7M4.84
    28 November 20258.6M-11.5%2.2M3.89
    14 November 20259.7M+13.2%4.8M2.01
    31 October 20258.5M-0.4%1.8M4.82
    15 October 20258.6M-16.6%2.3M3.71
    30 September 202510.3M+12.7%1.5M7.09
    15 September 20259.1M-1.9%1.6M5.55
    29 August 20259.3M+1.1%1.3M7.01
    15 August 20259.2M+8.0%3.4M2.68
    31 July 20258.5M+2.7%2.4M3.55
    15 July 20258.3M-7.3%1.6M5.18
    30 June 20258.9M-0.8%1.5M5.83
    13 June 20259.0M-3.4%1.3M7.03
    30 May 20259.3M+33.4%2.4M3.88
    15 May 20257.0M-16.6%3.0M2.34
    30 April 20258.4M-8.2%1.3M6.62
    15 April 20259.1M-0.7%2.0M4.46
    31 March 20259.2M+3.1%1.4M6.56
    14 March 20258.9M-8.2%1.6M5.47
    28 February 20259.7M-15.2%2.3M4.30
    14 February 202511.5M+6.0%3.3M3.46
    31 January 202510.8M+2.8%1.6M6.85
    15 January 202510.5M+7.1%1.5M7.07
    31 December 20249.8M+9.4%1.7M5.81
    13 December 20249.0M-1.5%1.5M5.94
    29 November 20249.1M-1.6%2.4M3.87
    15 November 20249.3M+8.9%3.5M2.66
    31 October 20248.5M-0.1%3.4M2.47
    15 October 20248.5M+31.5%2.4M3.52
    30 September 20246.5M+8.1%1.8M3.64
    13 September 20246.0M+8.6%1.6M3.70
    30 August 20245.5M+21.0%2.0M2.72
    15 August 20244.6M+1.9%2.1M2.14
    31 July 20244.5M-3.5%1.2M3.73
    15 July 20244.6M+7.5%915K5.07
    28 June 20244.3M+12.9%1.7M2.48
    14 June 20243.8M+3.1%1.2M3.12
    31 May 20243.7M-17.6%1.1M3.45
    15 May 20244.5M-9.0%2.5M1.80
    30 April 20244.9M+2.7%608K8.13
    15 April 20244.8M+4.9%618K7.79
    28 March 20244.6M-4.0%752K6.10
    15 March 20244.8M+4.7%1.2M4.13
    29 February 20244.6M-1.7%1.2M3.84
    15 February 20244.7M+2.4%1.6M2.88
    31 January 20244.5M-2.7%816K5.56
    12 January 20244.7M-11.5%812K5.75
    29 December 20235.3M+0.6%1.1M4.74
    15 December 20235.2M-9.4%1.0M5.05
    30 November 20235.8M-1.1%593K9.75
    15 November 20235.9M-10.4%850K6.88
    31 October 20236.5M+13.3%1.0M6.37
    13 October 20235.8M-1.7%876K6.57
    29 September 20235.9M+7.4%1.4M4.10
    15 September 20235.5M-2.2%657K8.30
    31 August 20235.6M+8.5%638K8.74
    15 August 20235.1M+7.4%955K5.38
    31 July 20234.8M-12.8%494K9.68
    14 July 20235.5M+3.7%624K8.79
    30 June 20235.3M-0.2%1.0M5.13
    15 June 20235.3M+11.4%765K6.92
    31 May 20234.8M+10.2%654K7.26
    15 May 20234.3M+5.1%1.1M3.78
    28 April 20234.1M+12.5%1.2M3.54
    14 April 20233.6M+6.3%920K3.96
    31 March 20233.4M+12.7%1.5M2.33
    15 March 20233.0M+1.2%1.3M2.35
    28 February 20233.0M+3.5%1.1M2.83
    15 February 20232.9M+7.3%748K3.89
    31 January 20232.7M-0.9%1.1M2.49
    13 January 20232.7M-16.2%663K4.12
    30 December 20223.3M+9.2%598K5.46
    15 December 20223.0M-3.4%1.2M2.49
    30 November 20223.1M+7.2%1.4M2.24
    15 November 20222.9M+15.7%411K7.02
    31 October 20222.5M-3.2%550K4.53
    14 October 20222.6M-2.1%379K6.79
    30 September 20222.6M-4.0%503K5.23
    15 September 20222.7M-3.8%308K8.91
    31 August 20222.8M+1.9%320K8.91
    15 August 20222.8M+2.2%571K4.90
    29 July 20222.7M+4.3%714K3.84
    15 July 20222.6M+32.0%1.2M2.27
    30 June 20222.0M-7.6%4.9M1.00
    15 June 20222.2M+15.9%446K4.83
    31 May 20221.9M+8.7%337K5.51
    13 May 20221.7M+7.6%560K3.05
    29 April 20221.6M+0.4%356K4.46
    14 April 20221.6M+0.8%250K6.31
    31 March 20221.6M+16.7%432K3.63
    15 March 20221.3M-1.7%376K3.57
    28 February 20221.4M-20.1%572K2.39
    15 February 20221.7M+44.4%337K5.08
    31 January 20221.2M+44.3%437K2.71
    14 January 2022821K+20.0%269K3.05
    31 December 2021685K+48.2%246K2.78
    15 December 2021462K+11.8%242K1.91
    30 November 2021413K-14.5%361K1.14
    15 November 2021483K-7.0%225K2.14
    29 October 2021519K+5.8%182K2.85
    15 October 2021491K-0.4%160K3.08
    30 September 2021493K-9.0%183K2.69
    15 September 2021541K+6.0%230K2.35
    31 August 2021511K-28.7%280K1.82
    13 August 2021717K-6.3%174K4.12
    30 July 2021764K+7.1%292K2.62
    15 July 2021714K-26.2%347K2.06
    30 June 2021967K-6.1%348K2.78
    15 June 20211.0M+1.3%204K5.04
    28 May 20211.0M+6.1%162K6.27
    14 May 2021958K+8.2%203K4.71
    30 April 2021885K+24.5%165K5.38
    15 April 2021711K+9.4%165K4.31
    31 March 2021650K+10.0%273K2.38
    15 March 2021590K+5.7%179K3.30
    26 February 2021558K+11.3%432K1.29
    12 February 2021502K+4.9%271K1.85
    29 January 2021478K-11.4%197K2.42
    15 January 2021539K+8.2%159K3.38
    31 December 2020499K+56.8%216K2.30
    15 December 2020318K+18.8%163K1.96
    30 November 2020268K+8.1%250K1.07
    13 November 2020247K-32.1%115K2.15
    30 October 2020364K-22.6%99K3.66
    15 October 2020471K-7.7%460K1.02
    30 September 2020510K+27.1%173K2.96
    15 September 2020401K-7.6%94K4.26
    31 August 2020435K-1.7%111K3.92
    14 August 2020442K-7.3%145K3.04
    31 July 2020477K-9.4%81K5.87
    15 July 2020527K+4.8%96K5.46
    30 June 2020502K+751.6%307K1.63
    15 June 202059K+2.7%124K1.00
    29 May 202057K-10.0%96K1.00
    15 May 202064K-18.0%77K1.00
    30 April 202078K-21.5%95K1.00
    15 April 202099K-13.7%54K1.82
    31 March 2020115K-24.6%108K1.07
    13 March 2020152K-0.1%109K1.40
    28 February 2020153K+33.0%272K1.00
    14 February 2020115K+53.3%102K1.12
    31 January 202075K+17.7%98K1.00
    15 January 202064K+37.7%48K1.33
    31 December 201946K-35.9%40K1.15
    13 December 201972K+5.5%67K1.08
    29 November 201968K-12.1%23K3.01
    15 November 201978K-11.0%69K1.12
    31 October 201987K-2.4%45K1.92
    15 October 201989K+23.7%24K3.69
    30 September 201972K+12.4%33K2.19
    13 September 201964K-2.0%25K2.53
    30 August 201966K-9.9%20K3.31
    15 August 201973K-10.8%36K2.00
    31 July 201982K-47.4%26K3.19
    15 July 2019155K+67.4%39K3.94
    28 June 201993K+121.2%109K1.00
    14 June 201942K+13.0%136K1.00
    31 May 201937K-38.8%32K1.17
    15 May 201961K+118.8%84K1.00
    30 April 201928K-0.9%56K1.00
    15 April 201928K+143.1%41K1.00
    29 March 201911K-46.0%36K1.00
    15 March 201921K+173.6%64K1.00
    28 February 20198K+72.1%89K1.00
    15 February 20195K-74.8%87K1.00
    31 January 201918K+24.5%81K1.00
    15 January 201914K+60.2%26K1.00
    31 December 20189K+36.9%197K1.00
    14 December 20187K-73.2%72K1.00
    30 November 201824K-7.9%37K1.00
    15 November 201827K-55.1%21K1.27
    31 October 201859K+115.5%97K1.00
    15 October 201827K-34.6%23K1.19
    28 September 201842K+13.5%118K1.00
    14 September 201837K+3.4%6K6.28
    31 August 201836K+8.0%11K3.29
    15 August 201833K-2.9%33K1.01
    31 July 201834K-2.5%9K3.66
    13 July 201835K-16.7%14K2.58
    29 June 201842K-11.1%31K1.36
    15 June 201847K-32.6%30K1.58
    31 May 201870K-18.9%17K4.13
    15 May 201886K-2.2%44K1.95
    30 April 201888K-4.5%57K1.55
    13 April 201892K+3.8%48K1.92
    29 March 201889K+8.1%57K1.57
    15 March 201882K+28.3%40K2.07
    28 February 201864K+45.2%106K1.00
    15 February 201844K+35.6%52K1.00
    31 January 201833K+32.0%58K1.00
    12 January 201825K-33.1%20K1.24
    29 December 201737K21K1.77
    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.