List of Message Fields

The following are descriptions of message fields which may be sent or received.

Table 1. List of Message Fields
FieldLengthData TypeDescription
Account16Text
  • Corresponds to Account (1) in Cboe FIX.
  • Reflected back on execution reports associated with this order. May be made available in the Member’s clearing file. Allowed characters are alphanumeric and colon.
AccessFee8AccessFee
  • Transaction fee or rebate, inclusive of earned tiers, for the trade.
AttributedQuote1Alphanumeric
  • Optional. Allows for an order to be attributed to a firm's MPID or optionally RTAL (for retail firms) in Cboe’s market data feeds. The order may also be included in attributed summary information displays related to quote/trade information on the Cboe website. Must opt-in to support through the Cboe Trade Desk.
  • N = Do not attribute firm MPID to this order
  • Y = Attribute firm MPID to this order
  • R = Attribute RTAL to this order
BaseLiquidityIndicator1Alphanumeric
  • Indicates whether the trade added or removed liquidity.
  • A = Added Liquidity
  • R = Removed Liquidity
  • X = Routed to Another Market
  • C = Auction/Uncrossing
  • W = Waiting for execution at pre-market time as dictated by TimeInForce value and "Hold Early to 7am" port setting. Only applied on the initial order acknowledgment.
CancelOrigOnReject1Alpha
  • Corresponds to CancelOrigOnReject (9619) in Cboe FIX. Indicates handling of original order on failure to modify.
  • N = Leave original order alone
  • Y = Cancel original order if modification fails
CancelReason1TextSingle character code for the cancellation reason. See Reason Codes for a list of possible reasons
CancelRejectReason1TextSingle character code for the cancellation Rejection reason. See Reason Codes or a list of possible reasons
CancelledOrderCount4BinaryNumber of orders cancelled. This field corresponds to CancelledOrderCount (7696) in Cboe FIX
Capacity1Alpha
  • Corresponds to OrderCapacity (47) in Cboe FIX.
  • A = Agency
  • P = Principal
  • R = Riskless Principal
ClOrdID20TextCorresponds to ClOrdID (11) in Cboe FIX. ID chosen by the client. Characters in the ASCII range 33-126 are allowed, except for comma, semicolon, pipe, the 'at' symbol and double quotes. If the ClOrdID matches a live order, the order will be rejected as duplicate.

Note: Cboe only enforces uniqueness of ClOrdID values among currently live orders. However, we strongly recommend that you keep your ClOrdID values unique
ClearingAccount4Text
  • Corresponds to OnBehalfOfSubID (116) and ClearingAccount (440) in Cboe FIX.
  • Supplemental identifier. Recorded and made available in execution reports. Available via Drop feeds.
ClearingFirm4Alpha
  • Corresponds to OnBehalfOfCompID (115) and ClearingFirm (439) Cboe FIX. MPID that will clear the trade. Must be an allowed NSCC MPID.
  • Port attribute value of Default EFID is used if not provided.
CmcMatchQty4BinaryCorresponds to CmcMatchQty (25023) in Cboe FIX. Matched size for CMC matching session.
CmcSessions2Text2 character field. Specifies the range of CMC sessions the order is eligible to participate in. If not specified CMC orders will be eligible to participate in all CMC matching sessions.
  • 1st Character: First CMC session the order is eligible to participate in. If the second character is not provided the order will only participate in this session.
  • 2nd Character: If provided, specifies the final CMC session the order is eligible to participate in.
  • A = 3:15 p.m.
  • D = 3:30 p.m.
  • L = 3:49 p.m.
  • S = 3:54 p.m. (Nasdaq-listed only)
ContraBroker4AlphanumericCorresponds to ContraBroker (375) in Cboe FIX. All externally matched (routed) executions will identify the away exchange.
  • AMEX= Routed to NYSE American
  • ARCA= Routed to NYSE Arca
  • BEX= Routed to Nasdaq Texas
  • CHX= Routed to NYSE Texas
  • ICRS = Routed to Intelligent Cross (pending approval)
  • IEX = Routed to Investors Exchange
  • INET = Routed to Nasdaq
  • LTSE = Routed to Long Term Stock Exchange
  • MEMX = Routed to Members Exchange
  • NYSE = Routed to NYSE
  • PERL = Routed to MIAX PEARL Exchange
  • PSX = Routed to Nasdaq PSX
  • NSX = Routed to NYSE National
  • DRT = Routed to DRT Pool
  • TFXE = Routed to 24X
  • TXSE = Routed to Texas Stock Exchange
  • BATS = Routed to Cboe BZX Exchange*
  • BYXX = Routed to Cboe BYX Exchange*
  • EDGA = Routed to Cboe EDGA Exchange*
  • EDGX = Routed to Cboe EDGX Exchange*
*Internally matched if ContraBroker matches the identifier of the local trading platform's book.
CorrectedPrice8 BinaryPrice For trade corrections, this is the new trade price. For trade breaks, this is set to 0.
CrossTradeFlag (BYX Only)1Alphanumeric
  • Corresponds to CrossTradeFlag (9355) in Cboe FIX.
  • Used to set eligibility for Periodic Auctions. Can be entered on individual orders or as a port setting.
  • 0 = None (to override port setting as necessary)
  • 1 = Periodic Auction Only
  • 2 = Periodic Auction Eligible
DiscretionAmount2BinaryCorresponds to DiscretionAmount (9622) in Cboe FIX.
  • Two implied decimal places (e.g., 10 = $0.10)
  • Discretion is implicitly added to bid prices and subtracted from offer prices
  • Order will be displayed at Price, but can be executed in the discretionary range.
  • A discretionary order will use the minimum amount of discretion necessary to achieve execution.
  • Maximum range is -9999 to 9999 (i.e., -99.99 to 99.99)
May not be used with IOC orders. May not be used with Post Only orders.
DisplayIndicator1Alphanumeric
  • Corresponds to DisplayIndicator (9479) in Cboe FIX.
  • Re-pricing Options:
  • V = Default. As determined by port level setting (defaults to S)
  • P = Price Adjust
  • m = Multiple Price Adjust
  • R = Cancel back the order if it cannot be booked and displayed without adjustment
  • r = Hidden; cancel back the order if it cannot be booked without adjustment
  • S = Display Price Sliding (this is to override an opt-out of Display Price Siding at the port level)
  • L = Display Price Sliding, but cancel back if order crosses the NBBO on entry
  • M = Multiple Display Price Sliding
  • h = Hidden Multiple Price Slide (effective 09/04/26)
  • Other Options:
  • v = Visible (for visible peg orders only; others will be rejected)
  • I = Invisible (implied for Midpoint Peg orders)
  • N = No Rescrape at Limit. Applicable only to fully routable, IOC orders (RoutingInst = R and TimeInForce = 3). After walking the price to the limit, there will be no final scrape at Cboe and the cancel reason code will state X (Expired) rather than N (No Liquidity).
DisplayPrice8Binary PriceOnly present when order is fully or partially booked. If the order has to be displayed at a less aggressive price for some reason, then that price will be reported here, otherwise equals Price. Present for hidden orders, indicating the price the order would have been displayed at.
DisplayRange4Binary
  • Corresponds to DisplayRange (8020) in Cboe FIX.
  • Used for random replenishment of reserve orders. Random replenishment establishes a range of possible values for the order quantity that is to be displayed. For example, if MaxFloor = 2,000, and DisplayRange = 200, the displayed quantity will be selected from one of the following values: 1,800, 1,900, 2,000, 2,100, or 2,200. Must be specified in round lots.
ExDestination1Text
  • Corresponds to ExDestination (100) in Cboe FIX.
  • Used to specify the designated away venue for RoutStrategy = DIRC and for RoutingInst = A (Post to Away).
  • A = NYSE American1
  • B = Nasdaq Texas1
  • C = NYSE National
  • F = Texas Stock Exchange1
  • G = 24X
  • H = MIAX Pearl
  • I = Investors Exchange
  • J = EDGA1
  • K = EDGX1,2
  • L = Long Term Stock Exchange
  • M = NYSE Texas
  • N = NYSE1
  • P = NYSE Arca1
  • Q = Nasdaq1
  • T = Intelligent Cross (pending approval)
  • U = MEMX
  • X = Nasdaq PSX
  • Y = BYX1
  • Z = BZX1
  • 1Post to Away option available for ROUT and ROUX only.
  • 2Post to EDGX (for ROUT, ROUX, ROUZ, and RDOT).
ExecID8BinaryCorresponds to ExecID (17) in Cboe FIX. Execution ID. Unique across all matching units on a given day. Note: ExecIDs will be represented on ODROP and FIXDROP ports as nine character, base 36 ASCII. Leading zeros should be added if the converted base 36 value is shorter than nine characters.
Table 2. Example Conversion
DecimalBase 36
28294005440239A1234B567
76335905726621R248BC23H
72855722818709AP05V2Z
ExecInst1Text
  • Corresponds to ExecInst (18) in Cboe FIX.
  • f = Intermarket Sweep (Directed or Book/Post only)
  • P = Market Peg (peg Buy [Sell] to NBBO Offer [Bid])
  • Q = Market Maker Peg (see Cboe Titanium U.S. Equities Market Maker Specification)
  • R = Primary Peg (peg Buy [Sell] to NBB Bid [Offer])
  • U = Supplemental Peg Order
  • M = Midpoint (peg to NBBO Midpoint)
  • m = Midpoint (peg to NBBO Midpoint, but do not match when NBBO is locked)
  • L = Alternate Midpoint (less aggressive of midpoint and 1 tick inside NBBO)
  • EDGA and EDGX:
  • d = Midpoint Discretionary Order
  • e = Midpoint Discretionary Order with Quote Depletion Protection
  • BZX:
  • r = Late (for use with Auction Only orders); see the Cboe Titanium U.S. Equities Auction Process Specification.
  • BZX and EDGX:
  • o = Listing Market Opening (for ROOC RoutStrategy only)
  • c = Listing Market Close (for ROOC RoutStrategy only)
  • a = Both Listing Market Open and Close (for ROOC RoutStrategy strategy only; also eligible for participation in halt auctions)
ExecRefID8BinaryCorresponds to ExecRefID (19) in Cboe FIX. Refers to the ExecID of the fill being cancelled or corrected.
ExpireTime8DateTime
  • Corresponds to ExpireTime (126) in Cboe FIX.
  • Required for TimeInForce = 6 orders, specifies the date-time (in UTC) that the order expires.
ExtExecInst1Text
  • Corresponds to ExtendedExecInst (9416) in Cboe FIX.
  • N = None
  • R = Retail Order, eligible for Retail rebate.
  • BYX and EDGX:
  • P = Retail Order (Price Improvement Only)
  • T = Retail Price Improving Order
  • EDGX:
  • X = Retail Priority Order, eligible for Retail Priority and Retail rebate rate.
FeeCode2Alphanumeric
  • Corresponds to FeeCode (9882) in Cboe FIX.
  • Indicates fee associated with an execution. Fee codes are published in the pricing schedule. New fee codes may be sent with little or no notice. Members are encouraged to code their systems to accept unknown fee codes.
InFlight2BinaryTotal number of messages received by the order handler which have not yet been acknowledged by the matching engine.
LastPx8Binary Price
  • Corresponds to LastPx (31) in Cboe FIX.
  • Price of this fill.
  • In MTP restatements, the price at which LastShares would have matched.
LastShares4Binary
  • Corresponds to LastShares (32) in Cboe FIX.
  • Executed share quantity.
  • In MTP restatements, this is the number of shares that would have matched.
LeavesQty4Binary
  • Corresponds to LeavesQty (151) in Cboe FIX.
  • Quantity still open for further execution. If zero, the order is complete.
LocateBroker4Alpha
  • Corresponds to LocateBroker (5700) in Cboe FIX.
  • Used for short sale orders to identify the broker that the short seller has identified as the source from which they will borrow the securities they are selling short.
LocateReqd1Alpha
  • Corresponds to LocateReqd (114) in Cboe FIX.
  • Optional, only processed for Sell Short and Sell Short Exempt orders.
  • N = Client affirms ability to borrow (default)
  • Y = Client does not affirm ability to borrow (results in reject)
MassCancelID20Text
  • Corresponds to MassCancelID (7695) in Cboe FIX.
  • Copied from the MassCancelID passed on the original Purge Orders message.
MassCancelInst8Text
  • Corresponds to MassCancelInst (7700) in Cboe FIX. Used for specification of Purge Orders message functionality.
  • At least one character must be provided (MPID Filter). Contiguous characters must be specified up to total length. Truncated/unspecified characters will default to values indicated (D) below.
  • 1st Character: MPID Filter
  • A = No filtering by MPID is performed.
  • F = All orders that were sent under the clearing relationship specified in ClearingFirm field. If F is specified and ClearingFirm not provided, the Mass Cancel or Purge request will be rejected.
  • 2nd Character: Acknowledgment Style
  • M = (D) Order Cancelled messages are sent for each cancelled order. If M is set and the MassCancelID optional field is specified, the MassCancelID value is ignored.
  • S = A single Purge Acknowledgment message is sent once all cancels have been processed. The MassCancelID optional field must be specified or the o Purge Orders message will be rejected.
  • B = Both individual Order Cancelled and Purge Acknowledgment messages will be sent. Also requires MassCancelID optional field to be specified or the Purge Orders message will be rejected.
  • 3rd Character: Lockout Instruction
  • N = (D) No lockout
  • L = Lockout until corresponding RiskReset received. Lockout can be used only with MPID Filter set to F, otherwise the Purge Orders message will be rejected. Lockout will apply to all New Order and Modify Order messages for the ClearingFirm (and symbol or RiskGroupIDs, if specified).
  • A self-imposed lockout can be released using the ResetRiskUSEquitiesV1 message.
MaxFloor4Binary
  • Corresponds to MaxFloor (111) in Cboe FIX.
  • Portion of OrderQty to display. The balance is reserve. 0 displays the entire quantity. The displayed quantity of each order at a price level is decremented first. When the displayed quantity is decremented below one round lot, it is is reloaded up to MaxFloor from reserve.
  • Default = 0
MinQty4Binary
  • Corresponds to MinQty (110) in Cboe FIX.
  • Minimum fill quantity for non-routable hidden or non-routable IOC orders which only interact with liquidity on the target Cboe Exchange.
  • Ignored if Enable True MinQty = No and the order is a routable displayed or routable IOC.
  • Order is rejected if Enable True MinQty = Yes and the order is a routable displayed or routable IOC.
  • Default is zero. Odd lot and mixed lot quantities allowed.
  • When the remaining size on an order is less than the defined MinQty, then MinQty will be automatically set to the remaining size.
  • When Enable True MinQty = No, the minimum total fill size may be made up of several consecutive smaller fills. Setting this port attribute to Yes will require every fill to meet the defined MinQty. See US Equities BOE Port Attributes for details.
  • If Enable True MinQty = Yes, orders will be converted into standard MinQty during a Periodic Auction. Periodic Auction Eligible orders will remain as True MinQty in the continuous book (BYX Only).
ModifyRejectReason1TextSingle character code for the Modify Rejection reason. See Reason Codes for a list of possible reasons
OrderQty4Binary
  • Corresponds to OrderQty (38) in Cboe FIX.
  • Order quantity. System limit is 999,999 shares.
  • On Order Restated messages, the OrderQty may be updated (for example, for SWP or CMC restatements).
OrderRestatementReason1Text
  • The reason for this Order Restated message.
  • C=Cboe Market Close (CMC)
  • L=Reload
  • P=Peg or Price Sliding Reprice
  • Q=Liquidity Updated
  • R=Reroute
  • S=Reduction of OrderQty due to SWP
  • W=Wash or MTP Decrement
  • Cboe reserves the right to add new values as necessary without prior notice.
OrdType1Alphanumeric
  • Corresponds to OrdType (40) in Cboe FIX.
  • 1 = Market
  • 2 = Limit (default)
  • 3 = Stop
  • 4 = Stop Limit
  • P = Pegged
  • Pegged requires ExecInst be set to L, M, m, P, Q, or R.
  • Market implies a TimeInForce of Day. Market day orders post in LULD straddle state or if a short sale during a Regulation SHO short sale circuit breaker.
  • Pegged orders may not be routable except for midpoint pegs BYX where RoutStrategy = RMPT, RMPL, or DIRC.
  • Effective 12/07/26, Pegged orders entered without a Price (44) are only accepted during RTH.
OrderID8Binary Corresponds to OrderID (37) in Cboe FIX. Base 36 ASCII. Order identifier supplied by Cboe. This identifier corresponds to the identifiers used in Cboe market data products.
OrderRejectReason1TextSingle character code for an order rejection reason. See Reason Codes for a list of possible reasons
OrigClOrdID20TextCorresponds to OrigClOrdID (41) in Cboe FIX.
OrigTime8DateTimeCorresponds to OrigTime (42) in the Cboe FIX. The date and time of the original trade, in GMT
PegDifference8Signed Binary Price
  • Corresponds to PegDifference (211) in Cboe FIX.
  • Optional signed value up to four decimal places1, when the peg difference is below $1.00, is added to the result of peg calculation. When the peg difference is above $1.00 a maximum of two decimal places can be specified.
  • Previously was required to be only a non-aggressive offset. Must be zero for non-pegged orders.
  • Default is zero for Midpoint Discretionary Orders with ExecInst = d.
  • Default is $0.01 (-$0.01) for sell (buy) Midpoint Discretionary Orders with ExecInst (18) = e.
  • Displayed Primary Peg orders with non-aggressive offset must have TimeInForce = R (Regular Hours Only) or 0 (Day). Day orders must be submitted after 9:30 a.m. ET.
  • On BYX and EDGX: If ExtExecInst = T (Retail Price Improving order):
  • May be priced in $0.001 increments
  • Must be ≥ 0 for Buy orders
  • Must be ≤ 0 for Sell orders
  • 1PegDifference is rounded (down for buy, up for sell) to fit the tick size.
  • For Periodic Auction Only orders, aggressive offsets only for primary peg orders.
  • No restrictions for Periodic Auction Eligible orders. Orders with passive offsets will be rejected.
PreventMatch3Alpha
  • Corresponds to PreventMemberMatch (7928) in Cboe FIX.
  • Three characters:
  • 1st character: MTP Modifier:
  • N = Cancel Newest
  • O = Cancel Oldest
  • B = Cancel Both
  • S = Cancel Smallest
  • D = Decrement larger / Cancel Smaller
  • d = Same as D above, but only decrement LeavesQty. Do not restate OrderQty.
  • 2nd character: Unique ID Level:
  • F = Prevent Match at Firm (Member) Level
  • M = Prevent Match at MPID Level
  • X = Prevent Match at the Affiliate (Exchange Member) or Sponsored Participant Level
  • 3rd character: Trading Group ID (optional):
  • Member specified alphanumeric value 0-9, A-Z, or a-z.
  • The Unique ID level (character 2) of both orders must match to prevent a trade. If specified on both orders, Trading Group ID (character 3) must match to prevent a trade.
  • The MTP Modifier (character 1) of the inbound order will be honored, except that if the inbound order specifies Decrement and the resting order does not, and the resting order is larger, then both orders will be cancelled. This exception is to protect the order entry software for the resting order from receiving an unexpected restatement message.
  • If order entry software is prepared to handle unexpected restatement messages, this exception may be overridden at the port level by requesting Allow MTP Decrement Override functionality.
  • Uses of MTP Modifier D or d and users of Allow MTP Decrement Override functionality must be prepared to receive an Order Restated message that decrements LeavesQty (and, for method D, OrderQty as well).
  • Match Trade Prevention will be supported for Periodic Auctions (BYX only).
Price8Binary Price
  • Corresponds to Price (44) in Cboe FIX.
  • Limit price. Six implied decimal places.
  • Required for limit orders (OrdType = 2). If specified on market order (OrdType = 1), the order will be rejected.
  • This field is also used to specify an optional cap price for pegged orders.
PurgeRejectReason1TextSingle character code for a purge rejection reason. See Reason Codes or a list of possible reasons
RiskGroupID2Binary
  • Corresponds to RiskGroupID (7699) in Cboe FIX for New Order and Purge Orders messages.
  • Used to group orders for use in Purge Orders messages where multiple orders can be cancelled by specifying a list of RiskGroupIDs.
RiskGroupIDCnt1BinaryNumber of repeating RiskGroupID values included in this message.
RiskReset8Text
  • Corresponds to RiskReset (7692) in Cboe FIX.
  • For use by customers to release MPID, symbol or RiskGroupID level lockout conditions resulting from self-imposed lockouts issued via Purge Orders messages.
  • Single Character Values:
  • S = Symbol level lockout reset
  • F = MPID level lockout reset
  • C = RiskGroupID lockout reset
  • Values may be combined together to allow for resets of multiple self-imposed lockouts in a single message. For example, FS, SC, FC, and SFC are all acceptable values.
  • If orders have been locked out any level, inbound orders for the locked symbol MPID or RiskGroupID will be rejected until this field is filled with the appropriate value on a ResetRiskUSEquitiesV1 message.
RiskResetResult1Text
  • <space> = Ignored; exceeds 1 reset per 100 milliseconds
  • C = Rejected; exceeds Risk Group ID limit
  • D = Rejected; automatic risk resets are disabled
  • E = Rejected; empty ResetRisk field
  • F = Rejected; exceeds firm reset limit
  • I = Rejected; incorrect data center
  • M = Rejected; invalid matching unit
  • S = Rejected; exceeds symbol reset limit
  • U = Rejected; invalid Symbol
  • Y = Success
  • c = Rejected; invalid ClearingFirm
  • y = Rejected; in replay
  • Additional reject values may be added in the future with no notice.
RiskStatusID16Text
  • User defined identifier of a Reset Risk message.
RouteDeliveryMethod3Text
  • Corresponds to RouteDeliveryMethod (9350) in Cboe FIX.
  • RTI = Route to improve (default if not specified). Ability to receive price improvement will take priority over speed of execution.
  • RTF = Route to Fill. Speed of execution will take priority over potential price improvement.
  • Only applicable to RoutStrategy = ROUT, ROUX, and ROUE.
RoutingInst4Text
  • Corresponds to RoutingInst (9303) in Cboe FIX.
  • 1st character:
  • B = Book Only (not routable, will remove from local book)1
  • P = Post Only (not routable)2
  • R = Routable
  • S = Super Aggressive - Cross or Lock (order will be removed from the book and routed to any away quote that is locking or crossing the order). May remove liquidity after posting.
  • X = Aggressive - Cross or Lock (order will be removed from the book and routed to any away quote that is locking or crossing the order)
  • K = Super Aggressive When Odd Lot (routable order will be automatically assigned Super Aggressive status when it becomes an odd lot)
  • A = Post to Away (a limit order that will post remainder to an away venue specified in ExDestination for applicable routing strategies)
  • N = Non-Displayed Swap - Book only, Hidden order that may remove liquidity after posting. Requires DisplayIndicator = I.
  • 2nd character (for use with RoutStrategy = DIRC, TRIM, SLIM, SLIM+ only):
  • D = Eligible to route to DRT
  • L = Route to displayed markets only
RoutStrategy6Text
  • Corresponds to RoutStrategy (9400) in Cboe FIX.
  • Please note:
  • DRT: Dark Routing Technique
  • LCPMC: Low Cost Protected Market Centers
  • All exchanges:
  • ALLB = Book + IOC Other Cboe Exchanges
  • RDOT = Book + DRT + IOC/Day NYSE
  • ROUT = Book + DRT + Street (default)
  • ROUX = Book + Street
  • ROUZ = Book + DRT
  • SWPA = ISO Sweep of All Protected Markets
  • DIRC = Book + DRT + Directed IOC or Directed ISO if ExecInst = f. ExDestination must also be sent.
  • EDGA/EDGX:
  • ROUC = Book + DRT + LCPMC + All Other Protected Markets + Posts to EDGX (EDGX only) or EDGA (EDGA only)
  • BYX:
  • DIRC = Book + Midpoint IOC IEX (also requires Ordtype = P, ExecInst = M or m, and ExDestination = I)
  • RMPT = Book + Midpoint IOC Select DRT/Lit Venues + Post to Local Book if non-IOC (must be used in conjunction with Midpoint Peg order type)
  • RMPL = Book + Midpoint IOC RMPT Venues + Midpoint IOC RMPL Venues + Post to Local Book if non-IOC (must be used in conjunction with Midpoint Peg order type)
  • BYX:
  • TRIM = Book + NYSE National + Nasdaq Texas + (DRT)
  • SLIM = Book + LCPMC + (DRT) + LCPMC + All other protected markets
  • BZX:
  • TRIM = Book + BYX + NYSE National + Nasdaq Texas + NYSE American + (DRT)
  • SLIM = Book + BYX + LCPMC + (DRT) + LCPMC + All other protected markets
  • SLIM+ = BYX + BZX + LCPMC + (DRT) + LCPMC + All other protected markets1
  • BZX/EDGX:
  • ROOC = Listing Market Open + Book + DRT + Street + Listing Market Close2
  • 1Route to BYX prior to scraping BZX unless price improvement is available.
  • 2Can be used with ExecInst = a, c, or o to specify listing market opening/closing eligibility.
SecondaryOrderID8Binary
  • Corresponds to SecondaryOrderID (198) in Cboe FIX.
  • Denotes an alternative OrderID which is present on Cboe market data feeds (for example, to hide that a reserve (iceberg) order has reloaded). Or, OrderID of the contra side of a prevented match.
ShortAccount10TextSee Account.
ShortRoutingInst1TextSee RoutingInst, first character only.
Side1Alphanumeric
  • Corresponds to Side (54) in Cboe FIX.
  • 1 = Buy
  • 2 = Sell
  • 5 = Sell Short (client affirms ability to borrow)
  • 6 = Sell Short Exempt
StepUpAmount (BYX only)4Short Binary Price
  • Corresponds to StepUpAmount(25025) in Cboe FIX.
  • StepUpAmount is implicitly added to bid prices and subtracted from offer prices for Enhanced RPI (Retail Price Improvement) orders.
  • The StepUpAmount value is specified in 0.001 minimum increments.
  • The minimum value is 0.000 (default).
  • The maximum value is 99.999.
StopPx8Binary Price
  • Corresponds to StopPx (99) in Cboe FIX.
  • Stop price. Required if OrdType = 3 (Stop) or 4 (Stop Limit). Stop and Stop Limit orders will only be triggered off Last Sale Eligible trades.
SubLiquidityIndicator1Alphanumeric
  • Additional information about an execution. Cboe may add additional values without notice. Members must gracefully ignore unknown values.
  • ASCII NUL (0x00) = No Additional Information
  • E = Trade added RPI liquidity (BYX and EDGX only)
  • H = Trade added hidden liquidity
  • I = Trade added hidden liquidity that was price improved
  • J = Execution from first order to join the NBBO
  • P = Periodic Auction (BYX Only)
  • S = NBBO-Setter fee eligible
  • V = Visible liquidity add trade that was price improved
  • m = Midpoint peg order
  • s = Order set the NBBO but is not fee eligible
Symbol8Text
  • Corresponds to Symbol (55) in Cboe FIX.
  • Entire Cboe format
TargetMatchingUnit1Binary
  • Corresponds to MatchingUnit (25017) in Cboe FIX.
  • Matching unit number the Purge Orders message will be sent toward. If blank or 0, the Purge Orders message will be sent to all units. Incompatible with symbol-level purges, specifying both symbol and TargetMatchingUnit will cause the Purge Orders message to be rejected.
  • If both MassCancelInst = L and a MatchingUnit parameter specified, a lockout will occur and will impact only the specified matching unit. Subsequent risk resets will clear risk locks on all units.
Text60TextHuman readable text with more information about the reject reason.
TimeInForce1Alphanumeric
  • Corresponds to TimeInForce (59) in Cboe FIX.
  • 0 = Day (default) (Early Trading Session until end of Regular Session) (EDGX only effective 12/07/26: Overnight Trading Session until end of Regular Session)
  • 1 = GTC (allowed, but treated as Day)
  • 2 = At the Open (BZX only and Cboe listed securities only)
  • 3 = IOC (Portion not filled immediately is cancelled)
  • 4 = FOK (an IOC where the entire size must be filled, else the order will be cancelled back)
  • 5 = GTX (Early Trading Session until end of Post-Market Session) (EDGX only effective 12/07/26: Overnight Trading Session until end of Post-Market Session)
  • 6 = GTD (Early Trading Session; expires at earlier of ExpireTime or end of Post-Market Session) (EDGX only effective 12/07/26: expires at earlier of specified ExpireTime or end of Post-Market Session)
  • 7 = At the Close (BZX only and applicable to Cboe Listed securities and Cboe Market Close symbols
  • E = PRE (Pre-Market Trading Session until end of Regular Session)
  • R = RHO (Regular Hours/Session Only)
  • T = PTD (Pre-Market Trading Session; expires at earlier of specified ExpireTime or end of Post-Market Session)
  • X = PTX (Pre-Market Trading Session until end of Post-Market Session)
WorkingPrice8Binary Price
  • Corresponds to WorkingPrice (9690) in Cboe FIX.
  • If price had to be adjusted to a less aggressive value for some reason, then the adjusted price will be reported here, otherwise equals Price.