Iceberg (display_qty) orders are not supported on the Kraken

Error message

Iceberg (display_qty) orders are not supported on the Kraken WS batch path; use REST

What it means

Iceberg orders (with a visible `display_qty`) are not supported on Kraken's WebSocket batch-order path, so `build_batch_order` rejects any order whose display_qty is set and directs the caller to REST.

Source

Thrown at crates/adapters/kraken/src/execution/spot.rs:1006

    leverage: Option<u16>,
) -> anyhow::Result<KrakenWsBatchAddOrder> {
    let order_type = order.order_type();
    let side = match order.order_side() {
        OrderSide::Buy => KrakenOrderSide::Buy,
        OrderSide::Sell => KrakenOrderSide::Sell,
    };

    if matches!(
        order_type,
        OrderType::TrailingStopMarket | OrderType::TrailingStopLimit
    ) {
        anyhow::bail!(
            "Trailing stop orders are not yet supported on the Kraken WS batch path; use REST",
        );
    }

    if order.display_qty().is_some() {
        anyhow::bail!(
            "Iceberg (display_qty) orders are not supported on the Kraken WS batch path; use REST",
        );
    }

    let kraken_order_type = match order_type {
        OrderType::Market => KrakenOrderType::Market,
        OrderType::Limit => KrakenOrderType::Limit,
        OrderType::StopMarket => KrakenOrderType::StopLoss,
        OrderType::StopLimit => KrakenOrderType::StopLossLimit,
        OrderType::MarketIfTouched => KrakenOrderType::TakeProfit,
        OrderType::LimitIfTouched => KrakenOrderType::TakeProfitLimit,
        ty => anyhow::bail!("Unsupported order type for Kraken WS batch: {ty:?}"),
    };

    let is_limit_order = matches!(
        order_type,
        OrderType::Limit | OrderType::StopLimit | OrderType::LimitIfTouched
    );

View on GitHub (pinned to 18893faf8b)

Solutions

Submit iceberg orders via REST instead of the WS batch path
Remove display_qty (submit the full quantity) if iceberg behavior is not required
Exclude the iceberg order from the batch and send it individually over REST

Example fix

// before
let order = factory.iceberg_limit(...display_qty...);
batch_add_via_ws(vec![order]);
// after
client.submit_order_via_rest(order); // icebergs must go over REST

Defensive patterns

Strategy: validation

Validate before calling

if order.display_qty().is_some() {
    submit_via_rest(order); // icebergs unsupported on WS batch
} else {
    batch_add_via_ws(vec![order])?;
}

Type guard

fn is_non_iceberg(order: &OrderAny) -> bool { order.display_qty().is_none() }

Try / catch

match batch_result {
    Err(e) if e.to_string().contains("Iceberg") => submit_via_rest(order),
    r => r?,
}

Prevention

Check display_qty before adding an order to a WS batch
Submit icebergs over REST only
Clear display_qty accidentally set by order templates when iceberg behavior is not intended

When it happens

Trigger: Calling `batch_add_via_ws` with an order that has `display_qty` populated (OrderFactory-created iceberg orders).

Common situations: Executing large parent orders as icebergs while the execution setup routes adds through the WS batch API; accidentally leaving display_qty set on an order template.

Related errors

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/6686d03afd9652e0. Report an issue: GitHub.