Skip to main content
Livermore
Livermore
US stocksTW
ZHEN

Icon PLC

ICLR
Exchange
Nasdaq
Industry
Services-Commercial Physical & Biological Research
SEC CIK
0001060955

In the last 90 days, Icon PLC insiders filed 0 open-market purchases and 8 sales; 426 institutions reported holding it in 13F filings for Q2 2026, worth $13.9B in total; superinvestors Harris Associates (Oakmark) and Greenhaven Associates hold 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
2.37M
Shares, settlement Oct 30, 2026
Change
−594.1K
−20.0% vs. Oct 15, 2026
Days to cover
1.69
Short interest ÷ average daily volume
Average daily volume
1.40M
Shares, as reported by FINRA
Short interest by settlement date
Oct 31, 2024: 1,080,136 sharesNov 15, 2024: 1,283,319 sharesNov 29, 2024: 1,327,228 sharesDec 13, 2024: 1,515,522 sharesDec 31, 2024: 1,573,487 sharesJan 15, 2025: 1,613,522 sharesJan 31, 2025: 1,390,409 sharesFeb 14, 2025: 1,482,353 sharesFeb 28, 2025: 1,687,586 sharesMar 14, 2025: 1,610,854 sharesMar 31, 2025: 2,284,980 sharesApr 15, 2025: 1,910,680 sharesApr 30, 2025: 1,219,445 sharesMay 15, 2025: 1,525,071 sharesMay 30, 2025: 1,446,347 sharesJun 13, 2025: 1,734,599 sharesJun 30, 2025: 2,081,629 sharesJul 15, 2025: 2,224,295 sharesJul 31, 2025: 2,093,351 sharesAug 15, 2025: 2,174,103 sharesAug 29, 2025: 2,345,732 sharesSep 15, 2025: 2,852,170 sharesSep 30, 2025: 2,480,312 sharesOct 15, 2025: 2,251,815 sharesOct 31, 2025: 1,889,137 sharesNov 14, 2025: 1,898,717 sharesNov 28, 2025: 2,788,306 sharesDec 15, 2025: 2,785,807 sharesDec 31, 2025: 2,639,596 sharesJan 15, 2026: 2,742,161 sharesJan 30, 2026: 2,823,591 sharesFeb 13, 2026: 2,000,193 sharesFeb 27, 2026: 1,929,158 sharesMar 13, 2026: 2,029,053 sharesMar 31, 2026: 2,896,513 sharesApr 15, 2026: 3,094,555 sharesApr 30, 2026: 2,678,541 sharesMay 15, 2026: 3,292,216 sharesMay 29, 2026: 3,006,810 sharesJun 15, 2026: 3,240,155 sharesJun 30, 2026: 2,991,578 sharesJul 15, 2026: 2,596,851 sharesJul 31, 2026: 2,223,311 sharesAug 14, 2026: 2,220,474 sharesAug 31, 2026: 2,379,093 sharesSep 15, 2026: 2,626,654 sharesSep 30, 2026: 2,801,170 sharesOct 15, 2026: 2,968,059 sharesOct 30, 2026: 2,373,951 shares
Short interest in ICLR by settlement date
Settlement dateShort interestChangeChange %Avg. daily volumeDays to cover
Oct 30, 20262.37M−594.1K−20.0%1.40M1.69
Oct 15, 20262.97M+166.9K+6.0%799.9K3.71
Sep 30, 20262.80M+174.5K+6.6%1.10M2.54
Sep 15, 20262.63M+247.6K+10.4%948.0K2.77
Aug 31, 20262.38M+158.6K+7.1%475.3K5.01
Aug 14, 20262.22M−2.84K−0.1%638.3K3.48
Jul 31, 20262.22M−373.5K−14.4%963.4K2.31
Jul 15, 20262.60M−394.7K−13.2%610.7K4.25
Jun 30, 20262.99M−248.6K−7.7%1.24M2.42
Jun 15, 20263.24M+233.3K+7.8%1.11M2.92
May 29, 20263.01M−285.4K−8.7%1.19M2.52
May 15, 20263.29M+613.7K+22.9%937.6K3.51
Apr 30, 20262.68M−416.0K−13.4%1.81M1.48
Apr 15, 20263.09M+198.0K+6.8%788.4K3.92
Mar 31, 20262.90M+867.5K+42.8%938.4K3.09
Mar 13, 20262.03M+99.9K+5.2%1.19M1.71
Feb 27, 20261.93M−71.0K−3.6%2.02M1.00
Feb 13, 20262.00M−823.4K−29.2%4.99M1.00
Jan 30, 20262.82M+81.4K+3.0%732.1K3.86
Jan 15, 20262.74M+102.6K+3.9%1.15M2.39
Dec 31, 20252.64M−146.2K−5.3%616.6K4.28
Dec 15, 20252.79M−2.50K−0.1%1.03M2.71
Nov 28, 20252.79M+889.6K+46.9%1.13M2.47
Nov 14, 20251.90M+9.58K+0.5%633.7K3.00
Oct 31, 20251.89M−362.7K−16.1%1.20M1.57
Oct 15, 20252.25M−228.5K−9.2%836.8K2.69
Sep 30, 20252.48M−371.9K−13.0%926.8K2.68
Sep 15, 20252.85M+506.4K+21.6%1.29M2.20
Aug 29, 20252.35M+171.6K+7.9%793.9K2.95
Aug 15, 20252.17M+80.8K+3.9%1.05M2.07
Jul 31, 20252.09M−130.9K−5.9%2.18M1.00
Jul 15, 20252.22M+142.7K+6.9%1.03M2.16
Jun 30, 20252.08M+347.0K+20.0%1.25M1.66
Jun 13, 20251.73M+288.3K+19.9%1.16M1.49
May 30, 20251.45M−78.7K−5.2%1.20M1.21
May 15, 20251.53M+305.6K+25.1%2.11M1.00
Apr 30, 20251.22M−691.2K−36.2%2.17M1.00
Apr 15, 20251.91M−374.3K−16.4%1.28M1.49
Mar 31, 20252.28M+674.1K+41.9%912.8K2.50
Mar 14, 20251.61M−76.7K−4.6%1.06M1.52
Feb 28, 20251.69M+205.2K+13.9%1.18M1.43
Feb 14, 20251.48M+91.9K+6.6%803.4K1.85
Jan 31, 20251.39M−223.1K−13.8%923.7K1.51
Jan 15, 20251.61M+40.0K+2.5%991.0K1.63
Dec 31, 20241.57M+58.0K+3.8%801.7K1.96
Dec 13, 20241.52M+188.3K+14.2%1.15M1.32
Nov 29, 20241.33M+43.9K+3.4%1.44M1.00
Nov 15, 20241.28M+203.2K+18.8%1.73M1.00
Oct 31, 20241.08M−669.4K−38.3%1.91M1.00

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 ICLR by settlement date
Settlement dateSharesPriceValue
Oct 5, 2026130$162.05$21.1K
Sep 30, 2026239$170.35$40.7K
Sep 28, 20261$172.33$172.33
Sep 24, 2026100$163.90$16.4K
Sep 18, 202689$169.68$15.1K
Sep 16, 20262,433$172.45$419.6K
Sep 15, 202623,400$168.93$3.95M
Sep 11, 2026709$165.69$117.5K
Sep 4, 202617$163.58$2.78K
Sep 2, 2026756$161.40$122.0K
Sep 1, 202617$164.99$2.80K
Aug 31, 2026151$170.02$25.7K
Aug 27, 202675$168.93$12.7K
Aug 26, 20267,659$168.91$1.29M
Aug 25, 202636$173.48$6.25K
Aug 20, 2026757$172.49$130.6K
Aug 14, 20263,330$167.48$557.7K
Aug 10, 2026199$164.51$32.7K
Aug 6, 202694$163.51$15.4K
Aug 4, 2026512$158.41$81.1K
Aug 3, 202613,393$163.57$2.19M
Jul 27, 20267$165.76$1.16K
Jul 24, 20266$170.32$1.02K
Jul 23, 20261,522$167.28$254.6K
Jul 17, 20266,882$170.00$1.17M
Jul 16, 2026129$172.08$22.2K
Jul 15, 20261,373$167.97$230.6K
Jul 14, 202617$166.10$2.82K
Jul 9, 202615$165.47$2.48K
Jun 30, 2026201$172.99$34.8K

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 ICLR by trade date
Trade dateShort volumeShort exemptOff-exchange volumeShort volume ratio
Nov 10, 202677,844104263,90429.5%
Nov 9, 2026158,8793475,67633.4%
Nov 6, 2026145,43659645,94722.5%
Nov 5, 2026233,41945673,22434.7%
Nov 4, 2026192,0705583,87332.9%
Nov 3, 2026140,2421541,89725.9%
Nov 2, 2026143,908362328,81743.8%
Oct 30, 2026717,5206,8091,213,62159.1%
Oct 29, 2026295,0874,637787,14337.5%
Oct 28, 2026625,98319,9851,809,50034.6%
Oct 27, 2026163,9050390,55342.0%
Oct 26, 2026189,8171481,08539.5%
Oct 23, 2026247,3940439,19656.3%
Oct 22, 2026242,2651371,59165.2%
Oct 21, 2026231,3614,932438,48852.8%
Oct 20, 2026313,280191410,15876.4%
Oct 19, 2026227,0840304,17574.7%
Oct 16, 2026186,6571238,15978.4%
Oct 15, 2026220,9664342,18864.6%
Oct 14, 2026221,29937294,44175.2%
Oct 13, 2026151,0293294,58351.3%
Oct 12, 2026130,354153405,25932.2%
Oct 9, 2026146,8310397,86936.9%
Oct 8, 2026339,4651413,34882.1%
Oct 7, 2026182,7511,269358,68850.9%
Oct 6, 2026291,311200454,75364.1%
Oct 5, 2026206,025260469,61543.9%
Oct 2, 2026140,9481209,43767.3%
Oct 1, 2026193,33553294,45565.7%
Sep 30, 2026156,7520417,20737.6%

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 ICLR
Week ofTierATS sharesATS tradesOther OTC sharesOther OTC tradesATS share
Oct 5, 2026T21,774,22332,155542,3365,29176.6%
Sep 28, 2026T21,731,21234,214426,0957,61280.2%
Sep 21, 2026T21,985,94232,418447,0405,66581.6%
Sep 14, 2026T21,455,03027,341609,8445,81070.5%
Sep 7, 2026T21,592,60226,392600,0614,70772.6%
Aug 31, 2026T21,255,82727,120337,6795,49978.8%
Aug 24, 2026T2564,50618,162202,2664,23973.6%
Aug 17, 2026T2883,67223,100212,2974,35180.6%
Aug 10, 2026T2767,54318,628353,4545,10768.5%
Aug 3, 2026T21,145,24724,966361,3266,78676.0%
Jul 27, 2026T22,651,78239,833792,7009,74777.0%
Jul 20, 2026T21,417,05828,602369,6905,29879.3%