Skip to main content
Livermore
Livermore
US stocksTW
ZHEN

Westlake Corp

WLK
Exchange
NYSE
Industry
Industrial Organic Chemicals
SEC CIK
0001262823

No open-market purchases or sales by Westlake Corp insiders were filed in the last 90 days; 363 institutions reported holding it in 13F filings for Q2 2026, worth $2.90B 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
3.99M
Shares, settlement Oct 30, 2026
Change
−265.3K
−6.2% vs. Oct 15, 2026
Days to cover
4.38
Short interest ÷ average daily volume
Average daily volume
911.5K
Shares, as reported by FINRA
Short interest by settlement date
Oct 31, 2024: 1,094,405 sharesNov 15, 2024: 1,215,727 sharesNov 29, 2024: 1,300,267 sharesDec 13, 2024: 1,391,876 sharesDec 31, 2024: 1,618,720 sharesJan 15, 2025: 1,524,544 sharesJan 31, 2025: 1,496,169 sharesFeb 14, 2025: 1,535,412 sharesFeb 28, 2025: 1,537,983 sharesMar 14, 2025: 2,014,158 sharesMar 31, 2025: 2,689,762 sharesApr 15, 2025: 3,157,269 sharesApr 30, 2025: 2,789,568 sharesMay 15, 2025: 3,683,709 sharesMay 30, 2025: 3,544,976 sharesJun 13, 2025: 2,830,365 sharesJun 30, 2025: 3,024,004 sharesJul 15, 2025: 3,541,549 sharesJul 31, 2025: 4,351,578 sharesAug 15, 2025: 4,643,380 sharesAug 29, 2025: 4,401,873 sharesSep 15, 2025: 4,714,262 sharesSep 30, 2025: 4,449,184 sharesOct 15, 2025: 5,140,703 sharesOct 31, 2025: 5,200,752 sharesNov 14, 2025: 5,020,580 sharesNov 28, 2025: 6,197,433 sharesDec 15, 2025: 5,467,547 sharesDec 31, 2025: 6,195,597 sharesJan 15, 2026: 6,299,563 sharesJan 30, 2026: 6,098,743 sharesFeb 13, 2026: 5,554,114 sharesFeb 27, 2026: 5,018,091 sharesMar 13, 2026: 5,029,131 sharesMar 31, 2026: 4,453,477 sharesApr 15, 2026: 3,447,322 sharesApr 30, 2026: 3,483,406 sharesMay 15, 2026: 3,602,338 sharesMay 29, 2026: 3,741,497 sharesJun 15, 2026: 3,976,664 sharesJun 30, 2026: 4,867,899 sharesJul 15, 2026: 5,275,584 sharesJul 31, 2026: 4,833,608 sharesAug 14, 2026: 4,936,041 sharesAug 31, 2026: 5,677,941 sharesSep 15, 2026: 5,309,547 sharesSep 30, 2026: 4,867,702 sharesOct 15, 2026: 4,259,386 sharesOct 30, 2026: 3,994,130 shares
Short interest in WLK by settlement date
Settlement dateShort interestChangeChange %Avg. daily volumeDays to cover
Oct 30, 20263.99M−265.3K−6.2%911.5K4.38
Oct 15, 20264.26M−608.3K−12.5%1.09M3.90
Sep 30, 20264.87M−441.8K−8.3%725.2K6.71
Sep 15, 20265.31M−368.4K−6.5%715.4K7.42
Aug 31, 20265.68M+741.9K+15.0%717.5K7.91
Aug 14, 20264.94M+102.4K+2.1%1.33M3.70
Jul 31, 20264.83M−442.0K−8.4%998.1K4.84
Jul 15, 20265.28M+407.7K+8.4%1.18M4.48
Jun 30, 20264.87M+891.2K+22.4%1.35M3.62
Jun 15, 20263.98M+235.2K+6.3%846.9K4.70
May 29, 20263.74M+139.2K+3.9%971.3K3.85
May 15, 20263.60M+118.9K+3.4%1.45M2.49
Apr 30, 20263.48M+36.1K+1.1%981.6K3.55
Apr 15, 20263.45M−1.01M−22.6%1.06M3.25
Mar 31, 20264.45M−575.7K−11.5%1.29M3.46
Mar 13, 20265.03M+11.0K+0.2%1.43M3.52
Feb 27, 20265.02M−536.0K−9.7%1.39M3.60
Feb 13, 20265.55M−544.6K−8.9%1.50M3.71
Jan 30, 20266.10M−200.8K−3.2%1.34M4.55
Jan 15, 20266.30M+104.0K+1.7%1.53M4.12
Dec 31, 20256.20M+728.0K+13.3%1.27M4.89
Dec 15, 20255.47M−729.9K−11.8%1.93M2.84
Nov 28, 20256.20M+1.18M+23.4%1.84M3.37
Nov 14, 20255.02M−180.2K−3.5%1.20M4.18
Oct 31, 20255.20M+60.0K+1.2%1.34M3.89
Oct 15, 20255.14M+691.5K+15.5%1.19M4.33
Sep 30, 20254.45M−265.1K−5.6%1.11M4.01
Sep 15, 20254.71M+312.4K+7.1%900.7K5.23
Aug 29, 20254.40M−241.5K−5.2%1.17M3.77
Aug 15, 20254.64M+291.8K+6.7%1.48M3.13
Jul 31, 20254.35M+810.0K+22.9%1.21M3.59
Jul 15, 20253.54M+517.5K+17.1%1.09M3.26
Jun 30, 20253.02M+193.6K+6.8%1.26M2.40
Jun 13, 20252.83M−714.6K−20.2%1.54M1.84
May 30, 20253.54M−138.7K−3.8%1.67M2.12
May 15, 20253.68M+894.1K+32.1%1.40M2.63
Apr 30, 20252.79M−367.7K−11.7%557.9K5.00
Apr 15, 20253.16M+467.5K+17.4%926.8K3.41
Mar 31, 20252.69M+675.6K+33.5%1.07M2.50
Mar 14, 20252.01M+476.2K+31.0%683.7K2.95
Feb 28, 20251.54M+2.57K+0.2%804.9K1.91
Feb 14, 20251.54M+39.2K+2.6%556.1K2.76
Jan 31, 20251.50M−28.4K−1.9%535.1K2.80
Jan 15, 20251.52M−94.2K−5.8%569.8K2.68
Dec 31, 20241.62M+226.8K+16.3%602.2K2.69
Dec 13, 20241.39M+91.6K+7.1%688.6K2.02
Nov 29, 20241.30M+84.5K+7.0%423.1K3.07
Nov 15, 20241.22M+121.3K+11.1%712.2K1.71
Oct 31, 20241.09M+132.3K+13.8%405.3K2.70

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 WLK by settlement date
Settlement dateSharesPriceValue
Oct 2, 202623,837$62.47$1.49M
Aug 26, 2026100$74.80$7.48K
Aug 25, 202657,174$76.49$4.37M
Aug 14, 20263,087$80.19$247.5K
Aug 13, 20263,302$79.17$261.4K
Aug 12, 2026707$80.84$57.2K
Aug 10, 202616,067$77.47$1.24M
Jul 31, 202617,707$71.72$1.27M
Jul 24, 202622,782$75.23$1.71M
Jul 9, 202694$75.80$7.13K
Jun 29, 2026170$76.62$13.0K
Jun 26, 20269,368$76.54$717.0K
Jun 24, 20263,461$76.48$264.7K
Jun 12, 20264,836$87.27$422.0K
Jun 5, 202699$85.25$8.44K
Jun 4, 2026247$86.39$21.3K
May 22, 202663$88.10$5.55K
May 20, 2026230$88.66$20.4K
May 19, 2026138$91.46$12.6K
May 13, 2026101$96.54$9.75K
May 11, 2026770$93.85$72.3K
May 7, 20269,837$99.92$982.9K
May 5, 20261,941$114.87$223.0K
May 4, 20264$114.99$459.96
Apr 8, 202636,020$123.39$4.44M
Apr 6, 202620$119.40$2.39K
Apr 1, 20264,675$116.82$546.1K
Mar 31, 202633,998$116.00$3.94M
Mar 26, 202612,886$114.22$1.47M
Mar 25, 202667,404$114.09$7.69M

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 WLK by trade date
Trade dateShort volumeShort exemptOff-exchange volumeShort volume ratio
Nov 13, 2026183,3420286,48364.0%
Nov 12, 2026135,3380250,12154.1%
Nov 11, 2026136,804143213,07064.2%
Nov 10, 2026205,7450291,68170.5%
Nov 9, 2026221,985325330,49167.2%
Nov 6, 2026162,286123273,23159.4%
Nov 5, 2026402,2962613,85765.5%
Nov 4, 2026411,3020580,00970.9%
Nov 3, 2026289,0120488,73559.1%
Nov 2, 2026281,29213454,83461.8%
Oct 30, 2026262,9450401,34065.5%
Oct 29, 2026136,128104350,60538.8%
Oct 28, 2026136,2450244,07955.8%
Oct 27, 2026184,377137309,99359.5%
Oct 26, 2026134,859136335,36540.2%
Oct 23, 2026198,66115396,04250.2%
Oct 22, 2026230,0071,615500,77445.9%
Oct 21, 2026208,6941,437408,29251.1%
Oct 20, 2026174,5203,101230,96775.6%
Oct 19, 202697,5971,007192,63350.7%
Oct 16, 2026211,866693353,81159.9%
Oct 15, 2026132,51426265,99449.8%
Oct 14, 2026198,7193,434320,14362.1%
Oct 13, 2026137,4929274,88150.0%
Oct 12, 2026219,9510406,05954.2%
Oct 9, 2026170,5870283,59060.2%
Oct 8, 2026209,3280403,00651.9%
Oct 7, 2026279,452408441,29363.3%
Oct 6, 2026209,424279356,66858.7%
Oct 5, 2026181,961152370,38849.1%

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 WLK
Week ofTierATS sharesATS tradesOther OTC sharesOther OTC tradesATS share
Oct 19, 2026T11,338,05634,431503,2016,90772.7%
Oct 12, 2026T11,325,58833,401361,6376,24778.6%
Oct 5, 2026T11,557,66740,496461,6528,62477.1%
Sep 28, 2026T12,203,58747,5061,074,6799,89767.2%
Sep 21, 2026T1895,92429,690307,0466,79474.5%
Sep 14, 2026T1894,80335,499450,3846,95966.5%
Sep 7, 2026T1848,72429,392314,0786,09673.0%
Aug 31, 2026T1764,97129,921236,5896,16476.4%
Aug 24, 2026T11,029,77039,407350,5938,67374.6%
Aug 17, 2026T11,110,67838,432400,6386,42473.5%
Aug 10, 2026T11,426,43143,105375,4546,45479.2%
Aug 3, 2026T13,317,27366,584664,0419,48583.3%