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AtriCure, Inc.

ATRC
Exchange
Nasdaq
Industry
Surgical & Medical Instruments & Apparatus
SEC CIK
0001323885

In the last 90 days, AtriCure, Inc. insiders filed 0 open-market purchases and 7 sales; 251 institutions reported holding it in 13F filings for Q2 2026, worth $1.47B 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
4.89M
Shares, settlement Oct 30, 2026
Change
+3.40K
+0.1% vs. Oct 15, 2026
Days to cover
7.60
Short interest ÷ average daily volume
Average daily volume
643.5K
Shares, as reported by FINRA
Short interest by settlement date
Oct 31, 2024: 2,249,781 sharesNov 15, 2024: 1,673,159 sharesNov 29, 2024: 1,693,056 sharesDec 13, 2024: 1,599,565 sharesDec 31, 2024: 1,622,122 sharesJan 15, 2025: 1,471,566 sharesJan 31, 2025: 1,172,156 sharesFeb 14, 2025: 1,275,983 sharesFeb 28, 2025: 1,423,652 sharesMar 14, 2025: 1,695,754 sharesMar 31, 2025: 1,341,484 sharesApr 15, 2025: 1,343,830 sharesApr 30, 2025: 1,531,698 sharesMay 15, 2025: 1,563,123 sharesMay 30, 2025: 1,829,737 sharesJun 13, 2025: 1,559,980 sharesJun 30, 2025: 1,546,777 sharesJul 15, 2025: 1,515,237 sharesJul 31, 2025: 2,224,926 sharesAug 15, 2025: 1,954,982 sharesAug 29, 2025: 2,083,744 sharesSep 15, 2025: 2,056,018 sharesSep 30, 2025: 2,205,743 sharesOct 15, 2025: 2,045,448 sharesOct 31, 2025: 2,303,562 sharesNov 14, 2025: 2,553,773 sharesNov 28, 2025: 2,299,662 sharesDec 15, 2025: 2,499,141 sharesDec 31, 2025: 2,366,606 sharesJan 15, 2026: 2,509,848 sharesJan 30, 2026: 2,510,177 sharesFeb 13, 2026: 3,447,589 sharesFeb 27, 2026: 3,147,385 sharesMar 13, 2026: 3,414,361 sharesMar 31, 2026: 3,540,034 sharesApr 15, 2026: 3,613,453 sharesApr 30, 2026: 3,857,819 sharesMay 15, 2026: 4,430,275 sharesMay 29, 2026: 3,400,672 sharesJun 15, 2026: 3,443,829 sharesJun 30, 2026: 4,449,392 sharesJul 15, 2026: 4,864,713 sharesJul 31, 2026: 3,864,377 sharesAug 14, 2026: 3,922,615 sharesAug 31, 2026: 4,141,306 sharesSep 15, 2026: 4,279,518 sharesSep 30, 2026: 4,818,782 sharesOct 15, 2026: 4,886,394 sharesOct 30, 2026: 4,889,793 shares
Short interest in ATRC by settlement date
Settlement dateShort interestChangeChange %Avg. daily volumeDays to cover
Oct 30, 20264.89M+3.40K+0.1%643.5K7.60
Oct 15, 20264.89M+67.6K+1.4%937.5K5.21
Sep 30, 20264.82M+539.3K+12.6%1.85M2.61
Sep 15, 20264.28M+138.2K+3.3%1.18M3.62
Aug 31, 20264.14M+218.7K+5.6%718.5K5.76
Aug 14, 20263.92M+58.2K+1.5%642.5K6.10
Jul 31, 20263.86M−1.00M−20.6%1.04M3.72
Jul 15, 20264.86M+415.3K+9.3%856.7K5.68
Jun 30, 20264.45M+1.01M+29.2%1.25M3.56
Jun 15, 20263.44M+43.2K+1.3%706.7K4.87
May 29, 20263.40M−1.03M−23.2%844.3K4.03
May 15, 20264.43M+572.5K+14.8%979.6K4.52
Apr 30, 20263.86M+244.4K+6.8%809.7K4.76
Apr 15, 20263.61M+73.4K+2.1%639.4K5.65
Mar 31, 20263.54M+125.7K+3.7%560.7K6.31
Mar 13, 20263.41M+267.0K+8.5%609.2K5.60
Feb 27, 20263.15M−300.2K−8.7%783.1K4.02
Feb 13, 20263.45M+937.4K+37.3%922.8K3.74
Jan 30, 20262.51M+3290.0%464.2K5.41
Jan 15, 20262.51M+143.2K+6.1%591.1K4.25
Dec 31, 20252.37M−132.5K−5.3%328.1K7.21
Dec 15, 20252.50M+199.5K+8.7%621.8K4.02
Nov 28, 20252.30M−254.1K−10.0%518.3K4.44
Nov 14, 20252.55M+250.2K+10.9%553.6K4.61
Oct 31, 20252.30M+258.1K+12.6%584.6K3.94
Oct 15, 20252.05M−160.3K−7.3%362.1K5.65
Sep 30, 20252.21M+149.7K+7.3%390.0K5.66
Sep 15, 20252.06M−27.7K−1.3%479.1K4.29
Aug 29, 20252.08M+128.8K+6.6%364.7K5.71
Aug 15, 20251.95M−269.9K−12.1%564.4K3.46
Jul 31, 20252.22M+709.7K+46.8%781.0K2.85
Jul 15, 20251.52M−31.5K−2.0%358.5K4.23
Jun 30, 20251.55M−13.2K−0.9%445.5K3.47
Jun 13, 20251.56M−269.8K−14.7%491.6K3.17
May 30, 20251.83M+266.6K+17.1%460.4K3.97
May 15, 20251.56M+31.4K+2.1%752.1K2.08
Apr 30, 20251.53M+187.9K+14.0%752.5K2.04
Apr 15, 20251.34M+2.35K+0.2%478.3K2.81
Mar 31, 20251.34M−354.3K−20.9%611.9K2.19
Mar 14, 20251.70M+272.1K+19.1%655.6K2.59
Feb 28, 20251.42M+147.7K+11.6%536.8K2.65
Feb 14, 20251.28M+103.8K+8.9%548.2K2.33
Jan 31, 20251.17M−299.4K−20.4%614.6K1.91
Jan 15, 20251.47M−150.6K−9.3%638.9K2.30
Dec 31, 20241.62M+22.6K+1.4%362.7K4.47
Dec 13, 20241.60M−93.5K−5.5%369.4K4.33
Nov 29, 20241.69M+19.9K+1.2%393.4K4.30
Nov 15, 20241.67M−576.6K−25.6%594.8K2.81
Oct 31, 20242.25M−1.04M−31.6%741.5K3.03

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 ATRC by settlement date
Settlement dateSharesPriceValue
Oct 13, 20263,438$57.28$196.9K
Sep 25, 20261,570$60.77$95.4K
Sep 24, 202620,499$59.96$1.23M
Sep 21, 202663,982$58.10$3.72M
Sep 17, 20269,182$57.14$524.7K
Sep 16, 202633,848$56.22$1.90M
Sep 10, 202611,918$53.03$632.0K
Aug 25, 20263$49.28$147.84
Aug 24, 202670$48.98$3.43K
Aug 20, 2026182$47.61$8.67K
Aug 18, 2026178$44.77$7.97K
Aug 14, 202630$43.49$1.30K
Aug 13, 202657$43.56$2.48K
Aug 11, 20263,928$41.64$163.6K
Jul 22, 202653$34.51$1.83K
Jul 16, 2026222$34.54$7.67K
Jul 7, 202697$32.39$3.14K
Jun 15, 202667$28.79$1.93K
Jun 11, 2026876$27.51$24.1K
Jun 8, 20264$27.10$108.4
May 27, 202676$28.81$2.19K
May 13, 202612,384$26.69$330.5K
Mar 27, 20267,134$30.04$214.3K
Mar 23, 202669$29.18$2.01K
Mar 19, 20266,000$28.85$173.1K
Mar 6, 20264,285$30.31$129.9K
Feb 26, 20263,226$31.19$100.6K
Feb 19, 20267,214$32.26$232.7K
Feb 9, 20261,083$37.11$40.2K
Feb 4, 20267,857$38.07$299.1K

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 ATRC by trade date
Trade dateShort volumeShort exemptOff-exchange volumeShort volume ratio
Nov 10, 2026138,184122315,50143.8%
Nov 9, 2026194,8923,043353,23655.2%
Nov 6, 2026144,9060238,50760.8%
Nov 5, 2026273,6590413,39866.2%
Nov 4, 2026396,80599501,05879.2%
Nov 3, 2026250,1993,209628,12239.8%
Nov 2, 2026223,3620510,64443.7%
Oct 30, 2026194,2431,550361,91953.7%
Oct 29, 2026199,8651,939270,93473.8%
Oct 28, 2026167,2780267,77062.5%
Oct 27, 2026198,8810267,47374.4%
Oct 26, 2026226,7462,633328,03569.1%
Oct 23, 2026121,4347185,65665.4%
Oct 22, 2026118,437118172,48568.7%
Oct 21, 2026126,1762206,31461.2%
Oct 20, 2026109,5920167,07565.6%
Oct 19, 2026131,0960195,46767.1%
Oct 16, 2026176,279121234,68675.1%
Oct 15, 2026229,0570391,16558.6%
Oct 14, 2026194,843608318,23261.2%
Oct 13, 2026159,6915259,87461.4%
Oct 12, 2026176,1110286,69961.4%
Oct 9, 2026156,6010224,95769.6%
Oct 8, 2026135,1390201,90666.9%
Oct 7, 2026165,8400236,87270.0%
Oct 6, 2026171,210207296,96057.7%
Oct 5, 2026230,1600401,32957.3%
Oct 2, 2026507,20911855,92159.3%
Oct 1, 2026483,2544,528851,97456.7%
Sep 30, 2026200,408177404,13549.6%

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 ATRC
Week ofTierATS sharesATS tradesOther OTC sharesOther OTC tradesATS share
Oct 5, 2026T21,110,36731,474411,1575,34473.0%
Sep 28, 2026T22,554,44449,799635,9078,36880.1%
Sep 21, 2026T21,880,05448,465668,3478,73273.8%
Sep 14, 2026T22,493,45448,1651,874,7036,86257.1%
Sep 7, 2026T21,858,15545,149914,1634,94467.0%
Aug 31, 2026T21,660,85037,578479,9627,46377.6%
Aug 24, 2026T21,401,16426,095474,1796,13074.7%
Aug 17, 2026T21,274,13132,514431,3694,69874.7%
Aug 10, 2026T2794,67926,156317,4854,18071.5%
Aug 3, 2026T21,317,65533,611535,2405,50571.1%
Jul 27, 2026T22,018,39643,831611,8436,63076.7%
Jul 20, 2026T22,013,49335,789493,9554,21880.3%