nautechsystems/nautilus_trader · error

MarketToLimit order price not set

Error message

MarketToLimit order price not set

What it means

OrderAny::limit_px returns the limit price of the contained order. MarketToLimit orders store their price as Option<Price> (initially None; it is set when the order is converted to a limit order on the venue), so calling limit_px before a price exists panics with 'MarketToLimit order price not set'.

Source

Thrown at crates/model/src/orders/any.rs:316

pub enum LimitOrderAny {
    Limit(LimitOrder),
    MarketToLimit(MarketToLimitOrder),
    StopLimit(StopLimitOrder),
    TrailingStopLimit(TrailingStopLimitOrder),
    MarketOrderWithProtection(MarketOrder),
}

impl LimitOrderAny {
    /// Returns the limit price for this order.
    ///
    /// # Panics
    ///
    /// Panics if the `MarketToLimit` order price is not set.
    #[must_use]
    pub fn limit_px(&self) -> Price {
        match self {
            Self::Limit(order) => order.price,
            Self::MarketToLimit(order) => order.price.expect("MarketToLimit order price not set"),
            Self::StopLimit(order) => order.price,
            Self::TrailingStopLimit(order) => {
                order.price.expect("TrailingStopLimit order price not set")
            }
            Self::MarketOrderWithProtection(order) => {
                order.protection_price.expect("No price for order")
            }
        }
    }
}

impl PartialEq for LimitOrderAny {
    fn eq(&self, rhs: &Self) -> bool {
        match self {
            Self::Limit(order) => order.client_order_id == rhs.client_order_id(),
            Self::MarketToLimit(order) => order.client_order_id == rhs.client_order_id(),
            Self::StopLimit(order) => order.client_order_id == rhs.client_order_id(),
            Self::TrailingStopLimit(order) => order.client_order_id == rhs.client_order_id(),

View on GitHub (pinned to 18893faf8b)

Solutions

1. Only call limit_px for order types with a guaranteed price (Limit, StopLimit); handle MarketToLimit and TrailingStopLimit separately.
2. For MarketToLimit, read the price via a method returning Option<Price> or check order.price is Some first.
3. Wait for the order's price to be determined (e.g. after the PriceDetermined/updated event) before querying limit_px.

Example fix

// before
let px = order.limit_px(); // panics for MarketToLimit with no price
// after
let px = match order {
    OrderAny::MarketToLimit(o) => o.price, // Option<Price>
    _ => Some(order.limit_px()),
};

let px = match &order {
    OrderAny::MarketToLimit(o) => o.price,
    OrderAny::MarketOrderWithProtection(o) => o.protection_price,
    _ => Some(order.limit_px()),
};

fn safe_limit_px(order: &OrderAny) -> Option<Price> {
    match order {
        OrderAny::MarketToLimit(o) => o.price,
        OrderAny::TrailingStopLimit(o) => o.price,
        OrderAny::MarketOrderWithProtection(o) => o.protection_price,
        _ => Some(order.limit_px()),
    }
}

// limit_px panics, not returns Result; guard the variant before calling
let px = safe_limit_px(&order).expect("order has no price yet");

When it happens

Trigger: Calling OrderAny::limit_px() on an order that is OrderAny::MarketToLimit while order.price is still None, i.e. before the venue-side conversion has produced a limit price.

Common situations: Strategy or reporting code that calls limit_px uniformly across all order variants without first checking the order type, or processing a freshly-submitted MarketToLimit order that has not yet received its determined-price update.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• TrailingStopLimit order price not set
• No price for order
• in-flight mutex poisoned
• wallet balance mutex poisoned
• instrument update lock poisoned

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/6b100416b1e292e4. Report an issue: GitHub.