On July 1, 2014, the SEC published in the Federal Register an order approving a proposed rule change by CBOE (SR-CBOE 2014-039) to amend certain margin rules for volatility index options.
Please refer to MIAX Regulatory Circular 2014 52 for further details.
FTSE Mondo Visione Exchanges Index:
MIAX Options Exchange: Approved Rule Change—CBOE Margin Rules
Date 31/07/2014