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Ironwood Pharmaceuticals Inc

IRWD
Exchange
Nasdaq
Industry
Pharmaceutical Preparations
SEC CIK
0001446847

No open-market purchases or sales by Ironwood Pharmaceuticals Inc insiders were filed in the last 90 days; 212 institutions reported holding it in 13F filings for Q2 2026, worth $675.8M in total; no superinvestor holds it.

Four kinds of short-selling data, each measuring something different:

  • Short interest: shares sold short and not yet bought back, as of a settlement date. FINRA publishes it twice a month, about eight business days after the settlement date.
  • Daily short volume: shares sold short each day in off-exchange trades reported to FINRA. It counts trades, not open positions, and is published the next day.
  • Fails-to-deliver: shares not delivered by the settlement date. The SEC publishes them twice a month, about two weeks late.
  • ATS (dark pool) volume: weekly volume on alternative trading systems and other off-exchange venues. FINRA publishes it two to four weeks after the week.

More in the glossary.

Short interest

Shares sold short and not yet bought back, from FINRA, on every settlement date in the last two years.

Short interest
14.9M
Shares, settlement Oct 30, 2026
Change
−1.03M
−6.5% vs. Oct 15, 2026
Days to cover
9.84
Short interest ÷ average daily volume
Average daily volume
1.51M
Shares, as reported by FINRA
Short interest by settlement date
Oct 31, 2024: 10,956,401 sharesNov 15, 2024: 8,567,112 sharesNov 29, 2024: 11,218,535 sharesDec 13, 2024: 12,084,477 sharesDec 31, 2024: 9,217,937 sharesJan 15, 2025: 9,448,965 sharesJan 31, 2025: 10,754,287 sharesFeb 14, 2025: 10,702,566 sharesFeb 28, 2025: 12,052,713 sharesMar 14, 2025: 16,247,025 sharesMar 31, 2025: 11,250,189 sharesApr 15, 2025: 11,642,399 sharesApr 30, 2025: 8,798,365 sharesMay 15, 2025: 8,467,972 sharesMay 30, 2025: 8,226,613 sharesJun 13, 2025: 7,651,319 sharesJun 30, 2025: 7,475,343 sharesJul 15, 2025: 6,528,581 sharesJul 31, 2025: 5,382,745 sharesAug 15, 2025: 6,071,719 sharesAug 29, 2025: 6,063,890 sharesSep 15, 2025: 5,707,969 sharesSep 30, 2025: 5,166,794 sharesOct 15, 2025: 4,702,015 sharesOct 31, 2025: 4,762,545 sharesNov 14, 2025: 7,154,955 sharesNov 28, 2025: 7,464,531 sharesDec 15, 2025: 7,329,764 sharesDec 31, 2025: 8,147,450 sharesJan 15, 2026: 9,007,479 sharesJan 30, 2026: 9,464,516 sharesFeb 13, 2026: 11,159,224 sharesFeb 27, 2026: 12,917,285 sharesMar 13, 2026: 13,703,587 sharesMar 31, 2026: 17,904,692 sharesApr 15, 2026: 18,191,102 sharesApr 30, 2026: 17,266,421 sharesMay 15, 2026: 17,334,279 sharesMay 29, 2026: 15,018,969 sharesJun 15, 2026: 15,898,991 sharesJun 30, 2026: 16,230,028 sharesJul 15, 2026: 17,191,892 sharesJul 31, 2026: 16,542,403 sharesAug 14, 2026: 18,066,382 sharesAug 31, 2026: 17,654,677 sharesSep 15, 2026: 18,728,986 sharesSep 30, 2026: 15,567,942 sharesOct 15, 2026: 15,887,553 sharesOct 30, 2026: 14,860,120 shares
Short interest in IRWD by settlement date
Settlement dateShort interestChangeChange %Avg. daily volumeDays to cover
Oct 30, 202614.9M−1.03M−6.5%1.51M9.84
Oct 15, 202615.9M+319.6K+2.1%1.99M7.99
Sep 30, 202615.6M−3.16M−16.9%2.52M6.19
Sep 15, 202618.7M+1.07M+6.1%1.43M13.11
Aug 31, 202617.7M−411.7K−2.3%1.48M11.90
Aug 14, 202618.1M+1.52M+9.2%2.80M6.44
Jul 31, 202616.5M−649.5K−3.8%1.65M10.04
Jul 15, 202617.2M+961.9K+5.9%2.72M6.32
Jun 30, 202616.2M+331.0K+2.1%2.87M5.65
Jun 15, 202615.9M+880.0K+5.9%1.94M8.18
May 29, 202615.0M−2.32M−13.4%2.50M6.00
May 15, 202617.3M+67.9K+0.4%3.00M5.77
Apr 30, 202617.3M−924.7K−5.1%1.64M10.51
Apr 15, 202618.2M+286.4K+1.6%1.78M10.20
Mar 31, 202617.9M+4.20M+30.7%3.83M4.67
Mar 13, 202613.7M+786.3K+6.1%2.06M6.65
Feb 27, 202612.9M+1.76M+15.8%3.99M3.24
Feb 13, 202611.2M+1.69M+17.9%2.47M4.52
Jan 30, 20269.46M+457.0K+5.1%2.69M3.52
Jan 15, 20269.01M+860.0K+10.6%12.4M1.00
Dec 31, 20258.15M+817.7K+11.2%2.53M3.22
Dec 15, 20257.33M−134.8K−1.8%1.93M3.79
Nov 28, 20257.46M+309.6K+4.3%2.71M2.75
Nov 14, 20257.15M+2.39M+50.2%4.83M1.48
Oct 31, 20254.76M+60.5K+1.3%1.18M4.03
Oct 15, 20254.70M−464.8K−9.0%1.31M3.60
Sep 30, 20255.17M−541.2K−9.5%1.41M3.67
Sep 15, 20255.71M−355.9K−5.9%1.32M4.32
Aug 29, 20256.06M−7.83K−0.1%1.18M5.14
Aug 15, 20256.07M+689.0K+12.8%1.66M3.66
Jul 31, 20255.38M−1.15M−17.6%1.27M4.23
Jul 15, 20256.53M−946.8K−12.7%1.24M5.24
Jun 30, 20257.48M−176.0K−2.3%2.19M3.41
Jun 13, 20257.65M−575.3K−7.0%3.25M2.35
May 30, 20258.23M−241.4K−2.9%3.44M2.39
May 15, 20258.47M−330.4K−3.8%2.36M3.59
Apr 30, 20258.80M−2.84M−24.4%3.05M2.88
Apr 15, 202511.6M+392.2K+3.5%5.17M2.25
Mar 31, 202511.3M−5.00M−30.8%3.13M3.59
Mar 14, 202516.2M+4.19M+34.8%2.60M6.26
Feb 28, 202512.1M+1.35M+12.6%2.37M5.08
Feb 14, 202510.7M−51.7K−0.5%6.73M1.59
Jan 31, 202510.8M+1.31M+13.8%2.42M4.45
Jan 15, 20259.45M+231.0K+2.5%2.11M4.48
Dec 31, 20249.22M−2.87M−23.7%2.84M3.25
Dec 13, 202412.1M+865.9K+7.7%1.92M6.31
Nov 29, 202411.2M+2.65M+31.0%1.75M6.42
Nov 15, 20248.57M−2.39M−21.8%1.58M5.41
Oct 31, 202411.0M−975.0K−8.2%1.06M10.31

Fails-to-deliver

Shares that weren't delivered by the settlement date, from the SEC, for the last 30 dates with fails. The price is the previous day's closing price published by the SEC.

Fails-to-deliver in IRWD by settlement date
Settlement dateSharesPriceValue
Oct 5, 20261,050$3.64$3.82K
Sep 21, 2026169,040$4.36$737.0K
Sep 18, 20263,363$4.23$14.2K
Sep 4, 2026211$4.29$905.19
Aug 24, 202697$4.29$416.13
Aug 13, 20261$4.32$4.32
Aug 5, 202615,792$4.31$68.1K
Aug 4, 20262,400$4.42$10.6K
Jul 17, 20261$3.87$3.87
Jul 14, 20265$4.21$21.05
Jul 6, 20264,000$4.33$17.3K
Jul 1, 2026898$4.21$3.78K
Jun 30, 202650,143$4.30$215.6K
Jun 29, 2026185$4.13$764.05
Jun 26, 2026178$3.84$683.52
Jun 22, 2026788$3.54$2.79K
Jun 18, 2026208$3.52$732.16
Jun 15, 2026888$3.65$3.24K
Jun 11, 20268,172$3.35$27.4K
Jun 10, 2026911$3.22$2.93K
Jun 8, 20261,458$3.31$4.83K
Jun 1, 202633$3.57$117.81
May 28, 202688$3.71$326.48
May 27, 202688$3.90$343.2
May 22, 202652,100$3.85$200.6K
May 21, 2026181$3.92$709.52
May 19, 20262,543$3.50$8.90K
May 18, 20263$3.58$10.74
Apr 22, 202674,314$4.07$302.5K
Apr 21, 20261,171$4.42$5.18K

Daily short volume

Off-exchange short-sale volume, not short interest: shares sold short each day in trades reported to FINRA, for the last 30 trading days.

The short volume ratio isn't a sentiment gauge: market makers sell short to fill buy orders and to hedge, so short sales are usually about half of off-exchange volume.

Off-exchange short volume in IRWD by trade date
Trade dateShort volumeShort exemptOff-exchange volumeShort volume ratio
Nov 11, 2026293,4156001,041,50528.2%
Nov 10, 2026502,2631,5681,411,21535.6%
Nov 9, 2026919,6093,1912,382,77638.6%
Nov 6, 2026247,8595,1401,116,38422.2%
Nov 5, 2026523,89613,7191,665,87331.4%
Nov 4, 2026287,0260561,45351.1%
Nov 3, 2026252,471393803,68231.4%
Nov 2, 2026282,8361,127414,72968.2%
Oct 30, 2026439,4242,680670,74265.5%
Oct 29, 2026243,958196606,00340.3%
Oct 28, 2026419,20131678,47861.8%
Oct 27, 2026164,577333497,16533.1%
Oct 26, 2026280,377444452,43062.0%
Oct 23, 2026298,4073,738507,09858.8%
Oct 22, 2026180,53550337,36853.5%
Oct 21, 2026417,4513,695676,00961.8%
Oct 20, 2026388,03529732,01953.0%
Oct 19, 2026298,7581,859696,66542.9%
Oct 16, 2026688,65991,076,19564.0%
Oct 15, 2026529,366411955,61755.4%
Oct 14, 2026258,1485,460521,84749.5%
Oct 13, 2026454,8192,002845,50153.8%
Oct 12, 2026191,819347384,46049.9%
Oct 9, 2026444,290196683,94165.0%
Oct 8, 2026571,943330792,77872.1%
Oct 7, 2026711,7432,1301,073,73866.3%
Oct 6, 2026380,9294,708720,92852.8%
Oct 5, 2026511,28815994,44551.4%
Oct 2, 2026560,570931958,17758.5%
Oct 1, 2026553,45832,7381,008,82254.9%

ATS (dark pool) volume

Weekly volume on alternative trading systems (ATS) and other off-exchange (OTC) venues, from FINRA, for the last 12 weeks. ATS share is ATS volume ÷ (ATS + OTC volume), not a share of all trading.

Weekly ATS and OTC volume in IRWD
Week ofTierATS sharesATS tradesOther OTC sharesOther OTC tradesATS share
Oct 5, 2026T22,188,97819,5422,251,0526,66649.3%
Sep 28, 2026T21,353,51218,1723,136,9275,83930.1%
Sep 21, 2026T21,307,64223,0103,267,2886,55528.6%
Sep 14, 2026T21,395,45825,8582,798,4145,97233.3%
Sep 7, 2026T21,110,30818,2861,652,7815,50940.2%
Aug 31, 2026T21,358,15121,2301,620,8496,10745.6%
Aug 24, 2026T21,129,63516,3781,797,7595,42338.6%
Aug 17, 2026T21,448,75222,5211,318,2695,80752.4%
Aug 10, 2026T21,824,51829,3162,508,4957,83342.1%
Aug 3, 2026T22,353,97227,5675,956,8769,82528.3%
Jul 27, 2026T21,451,19721,1622,512,0087,96836.6%
Jul 20, 2026T21,007,95716,8851,396,8055,32841.9%