Company:  SIMPLEX TRADING, LLC
Form Type:  13F-HR
Filing Date:  10/28/2021 
CIK:  0001488542 
Address:  230 S. LASALLE STREET
SUITE 08-500
 
City, State, Zip:  CHICAGO, Illinois 60604 
Telephone:  312.360.2440 
Fiscal Year:  12/31 
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  FORM 13F-HR
    COVERSHEET
    SUMMARY PAGE
      REPORT SUMMARY
      OTHER MANAGERS
  INFORMATION TABLE DOCUMENT
    INFO TABLE