Our option trades files have the supporting information needed to provide context to trading activity. Included with each trade is the trade price and size, the exchange where the trade printed, the NBBO quote and depth, the underlying bid and ask, and each of the individual exchange markets. Trades from Global Trading Hours (GTH) will be included effective February 5, 2020. GTH trades will be signified by a time stamp between 3:00 am ET and 9:15 am ET. At this time only ^SPX and ^VIX trade during GTH.
Exchange ID Mapping: Exchange IDs
Trade Condition ID Mapping: Trade Condition IDs
After the column with "number_of_exchanges", there are unlabeled columns representing individual exchange quotes. This repeatable sequence populates columns according to this pattern: Exchange ID (see Exchange mappingExchange IDs), Bid Size, Bid, Ask Size, Ask.