Options Price Reporting Authority  The Options Price Reporting Authority (OPRA) provides, through market data vendors, last sale information and current options quotations from a committee of participant exchanges designated as the Options Price Reporting Authority. OPRA is a national market system plan that governs the process by which options market data are collected from participant exchanges, consolidated, and disseminated. Current OPRA participants include:   The Securities Industry Automation Corporation (SIAC) gathers the last sale and quote information from each of the participant exchanges. SIAC then consolidates and disseminates that data to approved vendors. The OPRA data feed provides:   SIAC is responsible for the OPRA systems and networks. CBOE serves as the OPRA administrator. A significant gauge of the level of options market data is messages per second (MPS). Messages per second is just that - the number of messages (i.e., options trade and quote data) reported to OPRA by the options exchanges during any given second of a trading day. Data volume has increased dramatically since the early 1990s, as illustrated in the following table. Commentators suggest that there are three underlying causes of the increase:   The OPRA MPS data rates are more than 60 times those seen in the equities market, and options data represents well over 75% of all market data.