nautechsystems/nautilus_trader · error · anyhow::Error

MarketToLimit order type is not supported by BitMEX

Error message

MarketToLimit order type is not supported by BitMEX

What it means

BitmexOrderType's TryFrom<OrderType> conversion rejects the Nautilus MarketToLimit order type because BitMEX has no equivalent order type. The conversion bails instead of silently mapping to something semantically different.

Source

Thrown at crates/adapters/bitmex/src/common/enums.rs:197

    /// Pegged order, price automatically tracks market.
    Pegged,
}

impl TryFrom<OrderType> for BitmexOrderType {
    type Error = anyhow::Error;

    fn try_from(value: OrderType) -> Result<Self, Self::Error> {
        match value {
            OrderType::Market => Ok(Self::Market),
            OrderType::Limit => Ok(Self::Limit),
            OrderType::StopMarket => Ok(Self::Stop),
            OrderType::StopLimit => Ok(Self::StopLimit),
            OrderType::MarketIfTouched => Ok(Self::MarketIfTouched),
            OrderType::LimitIfTouched => Ok(Self::LimitIfTouched),
            OrderType::TrailingStopMarket => Ok(Self::Pegged),
            OrderType::TrailingStopLimit => Ok(Self::Pegged),
            OrderType::MarketToLimit => {
                anyhow::bail!("MarketToLimit order type is not supported by BitMEX")
            }
        }
    }
}

impl BitmexOrderType {
    /// Try to convert from Nautilus OrderType with anyhow::Result.
    ///
    /// # Errors
    ///
    /// Returns an error if the order type is MarketToLimit (not supported by BitMEX).
    pub fn try_from_order_type(value: OrderType) -> anyhow::Result<Self> {
        Self::try_from(value)
    }
}

impl From<BitmexOrderType> for OrderType {
    fn from(value: BitmexOrderType) -> Self {

View on GitHub (pinned to 18893faf8b)

Solutions

1. Use OrderType::Market or OrderType::Limit instead of MarketToLimit for BitMEX orders
2. Add a validation/pre-check in the strategy that skips or rewrites MarketToLimit orders for the BitMEX venue
3. Implement a custom adapter-level translation if MarketToLimit semantics are required

Example fix

// before
let order = OrderFactory::market_to_limit(...); // bails on BitMEX
// after
let order = OrderFactory::limit(...); // BitMEX supports Limit/Market/Stop etc.

if order.order_type() == OrderType::MarketToLimit && order.instrument_id().venue() == *BITMEX_VENUE {
    return Err("MarketToLimit unsupported on BitMEX; use Market or Limit");
}

fn is_bitmex_supported_order_type(t: OrderType) -> bool {
    !matches!(t, OrderType::MarketToLimit)
}

When it happens

Trigger: Submitting or converting any order whose OrderType is MarketToLimit when translating to a BitMEX order type via TryFrom.

Common situations: Users configure strategy defaults to MarketToLimit (common on other venues like Binance) and route orders to the BitMEX adapter without overriding the order type.

Related errors

• Unsupported order type for Betfair: {other:?}
• Unsupported order type for Binance Futures: {order_type:?}
• GTD time in force is not supported for BitMEX order submit;
• OUO contingency type not supported by BitMEX
• BitMEX does not support {}-{:?}-{:?} bars

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/b968e966e13a1667. Report an issue: GitHub.