Options Auction Update Message Fields

Options Auction Update messages are used to disseminate price and size information and Composite Market bid and offer prices during Opening and Re-Opening (halt) auctions. The Auction Update messages are sent every five seconds during an opening period. Refer to the Cboe Titanium U.S. Options Opening Process for more information.

The Options Auction Update message has the following format:

Table 1. Options Auction Update
Field NameOffsetLengthType/(Value)Description
Length01BinaryLength of this message including this field.
Message Type110xD1 Options Auction Update Message
Time Offset24Time OffsetNanosecond offset from last unit timestamp.
Symbol68Printable ASCIISymbol right padded with spaces.
Auction Type141Alphanumeric
  • G=GTH Opening(C1 Only)
  • O=RTH Opening(C1 Only)
  • H=Halt Re-Opening
  • V=Volatility Opening
Reference Price158Binary Long PriceCollared VMIM price computed on the queuing book only.
Buy Contracts234BinaryCumulative Buy contracts at the Reference Price and above.
Sell Contracts274BinaryCumulative Sell contracts at the Reference Price and below.
Indicative Price318Binary Long PriceCollared VMIM price computed on the combined queueing book and the continuous book. Equal to Reference Price for options that do not have a GTH trading session.
Auction Only Price398Binary Long PriceUncollared VMIM price computed on the queuing book only.
Opening Condition471Alphanumeric
  • O=Would open
  • Q=Need quote to open
  • B=Need more buyers(C1 Only)
  • S=Need more sellers(C1 Only)
  • C=Crossed Composite Market
Composite Market Bid Price488Binary Long PriceBid Price of the prevailing Composite Market
Composite Market Offer Price568Binary Long PriceOffer Price of the prevailing Composite Market.
Total Length=64 bytes
Cboe Titanium U.S. Options Multicast TOP Specification - Options Auction Update | Cboe