Trading Status Message Fields

The Trading Status message is used to indicate the current trading status of an options contract on a Cboe exchange. A Trading Status message will be sent whenever a security’s trading status changes. The following summarizes the Trading Status values in the Cboe system:

• H = Halt state.
• Q = Queuing. Sent starting at 7:30 a.m. ET once orders can be accepted for queuing in preparation for the RTH open.
• T = RTH Trading. Sent when symbol is open for trading, at or after 9:30 a.m. ET.

A Trading Status message will also be sent:

• For a Regulatory Halt Q (Queuing) period in any symbol where the underlying has experienced a Regulatory Halt as well as the T (Trading) resumption for the same instrument.

  Table 1. Trading Status

  Field	Offset	Length	Value/Type	Description
  Length	0	1	Binary	Length of this message including this field.
  Message Type	1	1	0xAB	Trading Status message
  Timestamp	2	8	Binary	Timestamp of the matching engine trading status message emitted by the specified Market Center. Encoded as the number of nanoseconds since midnight.
  Symbol	10	8	Alphanumeric	Symbol right padded with spaces.
  Market Center	18	1	Alphanumeric	B = C1 W = C2 X = EDGX Z = BZX
  Halt Status	19	1	Alphanumeric	H = Halted Q = Quote-Only R = Opening Rotation T = Trading
  Reserved	20	1		Reserved
  Total Length = 21 bytes