7 Roszel Road, Suite 5-A Princeton, New Jersey 08540 T 609 897 7300 F 609 987 2201 July 31, 2015 Via Electronic Mail Ms. Elizabeth M. Murphy, Secretary U.S. Securities and Exchange Commission 100 F Street, NE Washington, DC 20549 RE: Pilot Report of Obvious Errors and Catastrophic Errors During Limit or Straddle States – June 2015 Dear Ms.

Murphy: The Miami International Securities Exchange, LLC (“MIAX” or the “Exchange”) respectfully submits the following pilot report to the SEC and the public that includes a dataset containing the data for each Straddle and Limit State in optionable stocks found in Appendix A. MIAX has evaluated the impact of Limit and Straddle States and assessed the impact of the operation of obvious and catastrophic error rules during such periods. MIAX observed two (2) reportable activities during the month of June 2015 that would support any impact of Limit and Straddle States and the impact of the operation of obvious and catastrophic error rules. If you have any questions or comments, please contact me at (609) 897-1466. Sincerely, Edward Deitzel Executive Vice President Chief Regulatory Officer cc: David Shillman Heidi Pilpel . Appendix A Obvious and Catastrophic Errors During Limit and Straddle States For the month of June 2015, the Exchange collected the following dataset containing the data for each Straddle and Limit State in optionable stocks. Stock Symbol ZTS ZTS Option Symbol ZTS-2015-06-26C-50.00 ZTS-2015-06-26C-50.50 Price Change GT 30 PCT After LULD Executed Volume TW Avg MBBO Spread TW Avg Quote Bid Size TW Avg Quote Ask Size High Execution Price Low Execution Price Trades Reviewed for Error Price Change GT 30 PCT in LULD STRADDLE 10 4.82 0.93 8.96 4.8 4.8 N/A 0 0 STRADDLE 20 4.82 0.93 8.96 4.8 4.8 N/A 1 0 LULD Start Time Straddle Limit Indicator 55:48.5 55:48.5 .