New Order Single (35=D)

Optional. Per-message trading account. When present, validated against the session Go Account ID (from SenderCompID). Mismatch → ExecutionReport reject.

Required. Client-assigned order ID (≤ 256 chars; UUID recommended). Duplicate → reject 103=6.

Required. Trading pair / product (e.g. TBTC-TUSD*, ETH-USD*).

Required. 1 = Buy, 2 = Sell.

Required. Order quantity in the currency of tag 15. Must be > 0. Precision follows the product Base Increment / Quote Increment for that currency.

Size orders with OrderQty (38) and Currency (15).

Increments are precision constraints, not minimums. baseIncrement and quoteIncrement define the permitted quantity precision (step size) for the denomination selected by Currency (15). Do not divide or otherwise combine increments to calculate a minimum order quantity.

Minimum order size comes from the Products REST response fields baseMinSize and quoteMinSize, which are independent minimums in their own currencies: see List Products. The FIX gateway does not provide product-rule discovery (no SecurityList or SecurityDefinition messages); fetch minimums and increments from the Products endpoint.

When baseMinSize is empty but quoteMinSize is set, a base-denominated order must still meet the quote-currency minimum after its value is calculated using the validation price, so the effective base minimum varies with price. (The Products REST response always includes both fields; unset minimums are returned as empty strings, not omitted.) For market and limit orders, both configured minimums are checked regardless of the quantity currency: a base-denominated order must still meet quoteMinSize, and a quote-denominated order must still meet baseMinSize.

Validation price: passive limit orders are validated against the submitted limit price; market and marketable-limit orders (limit price would execute immediately) are validated against an indicative market price observed at validation time. The validation price may differ from the price at which the order ultimately executes.

TWAP and SteadyPace orders are additionally subject to strategy-specific sizing rules, such as the SubOrderSize minimum under TargetStrategy (847); product minimums alone do not describe the sizing rules for every order type.

Example (precision is not a minimum): a product with baseIncrement 0.0001, an empty baseMinSize, and quoteMinSize 20.00 does not accept a minimum order of 0.0001 BTC. 0.0001 is only the allowed quantity precision. If BTC is priced at $40,000, a base-denominated order must be worth at least $20, i.e. at least 0.0005 BTC (a valid increment multiple). On rejection, Text (58) states the minimum in the currency whose limit was not met (the quote currency here), e.g. Amount must be at least 20 USD.

Required. Currency of OrderQty (38). Must be the product base or quote currency; determines base-unit vs quote-notional sizing. Both buy and sell are supported for base- and quote-denominated sizes. When absent or empty, defaults to the product base currency. Must match against currencies in List Currencies and be consistent with Product (55). Fetch product minimums and quantity precision from List Products.

Required. 1 = Market, 2 = Limit, 3 = Stop (market when triggered), 4 = Stop Limit.

When TargetStrategy (847) is absent: 1→Sweep, 2→Limit, 3/4→Stop. Tag 847 is not allowed with 40=3 or 40=4.

Required. Client order-creation time (UTC). Format YYYYMMDD-HH:MM:SS[.sss[sss]].

Conditional.

• Required when OrdType = Limit (40=2) (strategy Limit).
• Optional for TWAP / SteadyPace. When present, acts as a limit cap.
• Optional for Stop (40=3/40=4): present → stop-limit; absent → stop-market. Send Price with 40=4 (Stop Limit).

Must be > 0 when present. Precision: product QuoteDisplayPrecision.

Conditional. Trigger price. Required when OrdType is Stop or Stop Limit (40=3 or 40=4). Use only with Stop / Stop Limit orders.

Optional. 1 = GTC (default for Limit and Stop when omitted). 3 = IOC (Limit and Market orders only). 4 = FOK (Fill or Kill). 6 = GTD (requires ExpireTime 126).

Conditional. Expiration timestamp (UTC). Required when TimeInForce = GTD (59=6). Must not be set unless 59=6.

Optional. Scheduled activation time (UTC). Maps to REST ScheduledDate.

Optional. Execution strategy. 1 = Market/Sweep (requires 40=1), 2 = Limit (requires 40=2), T = TWAP (40=1 or 40=2), S = SteadyPace (40=1 or 40=2). When absent, derived from OrdType. Not allowed with 40=3 or 40=4.

Conditional. Count of strategy-parameter entries (repeating group with 958/959/960). Required for TWAP (847=T) and SteadyPace (847=S). Tag 959 is optional between each 958/960 pair.

Conditional (inside group 957). Parameter name.

TWAP (847=T):

SteadyPace (847=S):

Limit (847=2 or derived from 40=2):

Optional. Accepted for FIX compliance but ignored by the server on inbound orders; parameter types are inferred from the parameter name (958). Any listed value may be sent or the tag omitted entirely.

Conditional (with 958). Parameter value. BoundsControl and IntervalUnit must be lowercase on the wire.

Optional. BitGo custom tag. 1 = Funded (default when absent), 2 = Margin.