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

Ciena Corp. short interest

4.0M shares of Ciena were sold short at the 15 October 2026 settlement, near the bottom of its range over the last year (2.9M to 7.3M). Short sellers would need 1.2 days of normal trading to buy them back.

Shares sold short4.0Mat 15 Oct 2026
Change on the settlement before+3.0%-10% over a year
Days to cover1.16at 3.4M shares a day
Of shares in issue2.81%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 (2.9M to 7.3M), and the share price moved +44% 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 20264.0M+3.0%3.4M1.16
    30 September 20263.9M+7.7%2.7M1.44
    15 September 20263.6M+7.3%3.1M1.17
    31 August 20263.3M+14.5%1.7M1.99
    14 August 20262.9M-21.3%2.1M1.37
    31 July 20263.7M-7.1%2.3M1.62
    15 July 20264.0M+3.6%1.7M2.40
    30 June 20263.9M-19.1%4.1M1.00
    15 June 20264.8M+5.7%4.3M1.11
    29 May 20264.5M-0.5%2.1M2.15
    15 May 20264.5M+3.8%1.9M2.41
    30 April 20264.4M-7.0%2.2M2.02
    15 April 20264.7M-21.5%3.0M1.59
    31 March 20266.0M+18.5%3.6M1.66
    13 March 20265.0M-19.4%3.3M1.52
    27 February 20266.3M+11.4%2.4M2.58
    13 February 20265.6M+32.4%6.4M1.00
    30 January 20264.2M-28.7%2.3M1.88
    15 January 20266.0M-8.4%2.7M2.23
    31 December 20256.5M-11.1%2.1M3.09
    15 December 20257.3M+14.1%3.6M2.01
    28 November 20256.4M+9.8%4.1M1.58
    14 November 20255.8M+42.4%3.2M1.84
    31 October 20254.1M-7.4%2.3M1.82
    15 October 20254.4M-8.8%2.5M1.78
    30 September 20254.9M+21.0%2.7M1.77
    15 September 20254.0M-15.7%4.2M1.00
    29 August 20254.8M-12.5%1.8M2.71
    15 August 20255.4M-5.3%1.7M3.29
    31 July 20255.7M+5.7%1.7M3.44
    15 July 20255.4M-12.1%2.3M2.34
    30 June 20256.2M+26.9%2.3M2.70
    13 June 20254.9M+29.6%3.8M1.27
    30 May 20253.8M-3.6%1.2M3.20
    15 May 20253.9M-7.2%1.6M2.41
    30 April 20254.2M-6.4%1.5M2.75
    15 April 20254.5M+13.4%2.7M1.68
    31 March 20254.0M-5.7%2.2M1.80
    14 March 20254.2M+11.7%3.7M1.13
    28 February 20253.8M-4.6%2.4M1.58
    14 February 20253.9M-19.4%1.9M2.03
    31 January 20254.9M-11.3%3.5M1.38
    15 January 20255.5M+19.4%1.8M3.11
    31 December 20244.6M-25.0%1.9M2.37
    13 December 20246.2M-1.6%3.4M1.81
    29 November 20246.3M+0.2%1.2M5.37
    15 November 20246.2M+3.5%1.7M3.74
    31 October 20246.0M-1.3%1.6M3.76
    15 October 20246.1M+3.7%2.6M2.38
    30 September 20245.9M-0.6%2.1M2.82
    13 September 20245.9M+3.1%2.6M2.30
    30 August 20245.8M+19.0%1.3M4.33
    15 August 20244.8M+9.6%1.4M3.37
    31 July 20244.4M+6.3%1.2M3.61
    15 July 20244.1M+3.1%1.0M4.08
    28 June 20244.0M+22.2%1.9M2.16
    14 June 20243.3M-38.7%2.4M1.36
    31 May 20245.4M-2.0%1.2M4.34
    15 May 20245.5M+5.6%1.2M4.40
    30 April 20245.2M+14.0%1.6M3.19
    15 April 20244.6M-13.7%1.5M2.96
    28 March 20245.3M+4.6%1.5M3.54
    15 March 20245.1M-15.8%4.2M1.21
    29 February 20246.0M+11.9%1.8M3.29
    15 February 20245.4M+16.3%1.8M2.93
    31 January 20244.6M+1.9%1.6M2.84
    12 January 20244.5M+10.4%1.7M2.66
    29 December 20234.1M+14.3%1.7M2.36
    15 December 20233.6M-2.2%2.7M1.34
    30 November 20233.7M-1.8%1.0M3.50
    15 November 20233.7M-7.1%1.0M3.64
    31 October 20234.0M+30.1%1.2M3.23
    13 October 20233.1M+3.1%1.5M2.12
    29 September 20233.0M-15.2%1.1M2.84
    15 September 20233.5M-0.4%1.7M2.11
    31 August 20233.5M+2.7%2.0M1.77
    15 August 20233.5M-11.2%1.3M2.56
    31 July 20233.9M+9.1%1.9M2.00
    14 July 20233.6M-13.6%2.0M1.77
    30 June 20234.1M-1.2%1.9M2.22
    15 June 20234.2M-3.0%3.5M1.19
    31 May 20234.3M-3.6%1.6M2.65
    15 May 20234.5M+13.6%1.5M3.03
    28 April 20233.9M-7.3%1.4M2.84
    14 April 20234.2M+8.6%1.6M2.65
    31 March 20233.9M+0.4%1.8M2.19
    15 March 20233.9M-5.4%2.6M1.49
    28 February 20234.1M+5.1%1.7M2.48
    15 February 20233.9M+1.7%1.4M2.82
    31 January 20233.8M-2.7%1.2M3.19
    13 January 20233.9M+1.1%1.3M3.06
    30 December 20223.9M+10.1%1.6M2.39
    15 December 20223.5M+2.4%3.1M1.15
    30 November 20223.5M-18.2%1.6M2.12
    15 November 20224.2M-15.1%1.9M2.27
    31 October 20225.0M-1.3%1.6M3.10
    14 October 20225.1M+3.0%1.4M3.61
    30 September 20224.9M-1.6%1.9M2.60
    15 September 20225.0M+31.3%2.9M1.72
    31 August 20223.8M-2.1%1.4M2.73
    15 August 20223.9M+4.9%958K4.04
    29 July 20223.7M-1.0%1.1M3.37
    15 July 20223.7M-1.7%1.1M3.52
    30 June 20223.8M-1.0%1.9M1.97
    15 June 20223.8M+10.8%2.1M1.86
    31 May 20223.5M+8.0%1.6M2.16
    13 May 20223.2M+16.3%1.3M2.47
    29 April 20222.8M+9.9%1.1M2.51
    14 April 20222.5M-4.0%1.0M2.46
    31 March 20222.6M-9.7%1.3M1.98
    15 March 20222.9M-37.9%2.5M1.18
    28 February 20224.7M-3.8%1.6M2.84
    15 February 20224.8M+69.5%1.8M2.72
    31 January 20222.9M-40.8%1.8M1.62
    14 January 20224.8M-12.6%1.8M2.65
    31 December 20215.5M-12.6%1.1M5.00
    15 December 20216.3M+85.7%2.6M2.40
    30 November 20213.4M+2.4%1.1M3.10
    15 November 20213.3M-19.7%1.1M3.15
    29 October 20214.1M+6.0%779K5.32
    15 October 20213.9M-5.4%717K5.45
    30 September 20214.1M-2.3%1.2M3.40
    15 September 20214.2M+8.7%1.6M2.59
    31 August 20213.9M+5.5%1.3M3.01
    13 August 20213.7M-10.8%668K5.51
    30 July 20214.1M-11.1%989K4.18
    15 July 20214.6M-11.2%895K5.19
    30 June 20215.2M+12.5%1.3M3.94
    15 June 20214.6M-0.3%2.1M2.27
    28 May 20214.7M-5.7%975K4.78
    14 May 20214.9M+11.1%1.4M3.56
    30 April 20214.5M+15.6%1.2M3.71
    15 April 20213.9M-4.3%857K4.50
    31 March 20214.0M-0.6%1.1M3.76
    15 March 20214.0M+31.8%1.8M2.26
    26 February 20213.1M-7.7%1.2M2.54
    12 February 20213.3M-16.1%983K3.39
    29 January 20214.0M-13.9%1.4M2.91
    15 January 20214.6M-16.1%1.4M3.32
    31 December 20205.5M+35.5%1.7M3.16
    15 December 20204.1M+37.3%2.3M1.78
    30 November 20203.0M+14.9%1.6M1.86
    13 November 20202.6M-16.3%1.5M1.77
    30 October 20203.1M-29.9%1.4M2.24
    15 October 20204.4M+29.9%1.9M2.36
    30 September 20203.4M-8.7%1.9M1.76
    15 September 20203.7M+26.1%5.7M1.00
    31 August 20202.9M-26.5%1.4M2.06
    14 August 20204.0M-12.5%1.1M3.57
    31 July 20204.6M+16.3%1.6M2.81
    15 July 20203.9M+4.3%1.8M2.17
    30 June 20203.8M+8.9%1.5M2.52
    15 June 20203.4M-27.4%2.3M1.49
    29 May 20204.7M-4.0%1.7M2.71
    15 May 20204.9M+38.3%1.5M3.36
    30 April 20203.6M-11.2%2.0M1.79
    15 April 20204.0M-5.7%2.1M1.90
    31 March 20204.3M-12.5%2.1M1.99
    13 March 20204.9M+6.1%2.8M1.76
    28 February 20204.6M-27.9%1.9M2.38
    14 February 20206.4M-7.6%1.5M4.21
    31 January 20206.9M-11.3%1.6M4.28
    15 January 20207.8M-8.4%1.4M5.52
    31 December 20198.5M-16.1%2.7M3.17
    13 December 201910.1M+14.0%5.9M1.72
    29 November 20198.9M+7.9%1.9M4.68
    15 November 20198.2M-7.4%1.9M4.23
    31 October 20198.9M+3.1%1.9M4.73
    15 October 20198.6M-2.7%2.5M3.51
    30 September 20198.9M+91.5%3.6M2.45
    13 September 20194.6M-12.2%4.5M1.04
    30 August 20195.3M+6.7%1.7M3.04
    15 August 20194.9M-12.8%1.9M2.67
    31 July 20195.7M+0.5%1.9M2.93
    15 July 20195.6M-0.1%2.6M2.18
    28 June 20195.7M+13.8%4.2M1.35
    14 June 20195.0M-16.0%4.8M1.04
    31 May 20195.9M-19.9%2.5M2.41
    15 May 20197.4M-8.2%2.6M2.80
    30 April 20198.0M-2.4%2.1M3.86
    15 April 20198.2M+10.7%2.2M3.82
    29 March 20197.4M+3.8%2.5M2.93
    15 March 20197.2M+13.2%3.7M1.93
    28 February 20196.3M+11.5%2.6M2.44
    15 February 20195.7M+5.2%1.7M3.27
    31 January 20195.4M-21.9%2.7M1.98
    15 January 20196.9M+3.2%2.8M2.48
    31 December 20186.7M+1.1%3.4M1.94
    14 December 20186.6M+8.3%4.6M1.44
    30 November 20186.1M-3.9%2.7M2.25
    15 November 20186.4M-35.8%4.1M1.54
    31 October 20189.9M-35.6%3.4M2.89
    15 October 201815.4M+4.0%2.7M5.75
    28 September 201814.8M-4.6%2.0M7.23
    14 September 201815.5M-14.2%2.8M5.52
    31 August 201818.1M+12.4%4.1M4.39
    15 August 201816.1M-4.9%1.2M12.99
    31 July 201816.9M-6.0%1.9M9.08
    13 July 201818.0M+5.5%1.7M10.68
    29 June 201817.1M-1.1%3.2M5.36
    15 June 201817.3M+6.0%3.4M5.10
    31 May 201816.3M+3.0%4.0M4.06
    15 May 201815.8M-2.3%3.0M5.22
    30 April 201816.2M-3.0%3.4M4.78
    13 April 201816.7M+3.5%2.3M7.20
    29 March 201816.1M-12.8%2.9M5.65
    15 March 201818.5M+3.6%5.8M3.22
    28 February 201817.9M-4.7%2.5M7.11
    15 February 201818.7M+0.5%3.9M4.81
    31 January 201818.6M+9.5%2.5M7.42
    12 January 201817.0M-0.5%2.3M7.30
    29 December 201717.1M2.4M7.13
    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.