nautechsystems/nautilus_trader · error

Invalid funding_rate value: {e}

Error message

Invalid funding_rate value: {e}

What it means

parse_funding_rate_msg converts an OKX funding-rate channel message into a FundingRateUpdate. The funding_rate field is a string that must parse as a Decimal; if OKX sends a malformed, empty, or unexpectedly formatted value, the parse fails and this error is raised wrapping the Decimal parse error.

Source

Thrown at crates/adapters/okx/src/common/parse.rs:561

    ))
}

/// Parses an [`OKXFundingRateMsg`] into a [`FundingRateUpdate`].
///
/// # Errors
///
/// Returns an error if the `funding_rate` field fails
/// to parse into a Decimal value or `next_funding_time` fails to parse into a positive, in bounds interval.
pub fn parse_funding_rate_msg(
    msg: &OKXFundingRateMsg,
    instrument_id: InstrumentId,
    ts_init: UnixNanos,
) -> anyhow::Result<FundingRateUpdate> {
    let funding_rate = msg
        .funding_rate
        .as_str()
        .parse::<Decimal>()
        .map_err(|e| anyhow::anyhow!("Invalid funding_rate value: {e}"))?;

    let funding_time = parse_millisecond_timestamp(msg.funding_time);
    let next_funding_time = parse_millisecond_timestamp(msg.next_funding_time);
    let funding_interval_nanos =
        next_funding_time
            .duration_since(&funding_time)
            .ok_or(anyhow::anyhow!(
                "Invalid funding_interval, cannot be negative"
            ))?;
    let funding_interval = u16::try_from(funding_interval_nanos.as_mins())
        .context("funding_interval out of bounds")?;
    let ts_event = parse_millisecond_timestamp(msg.ts);

    Ok(FundingRateUpdate::new(
        instrument_id,
        funding_rate,
        Some(funding_interval),
        Some(funding_time),

View on GitHub (pinned to 18893faf8b)

Solutions

1. Log msg.funding_rate and the full raw message when this fires to see the actual malformed value.
2. Handle empty/placeholder values by skipping the update (return Ok with early exit) rather than erroring the whole message batch.
3. Pre-sanitize: trim the string and reject empty before parse::<Decimal>(); consider accepting scientific notation via Decimal::from_scientific as a fallback.
4. Check the adapter version against the current OKX funding-rate channel schema in case the field format changed.

Example fix

// before
let funding_rate = msg
    .funding_rate
    .as_str()
    .parse::<Decimal>()
    .map_err(|e| anyhow::anyhow!("Invalid funding_rate value: {e}"))?;

// after
let raw = msg.funding_rate.as_str().trim();
if raw.is_empty() {
    anyhow::bail!("skipping funding rate update: empty funding_rate");
}
let funding_rate = raw.parse::<Decimal>()
    .map_err(|e| anyhow::anyhow!("Invalid funding_rate value: {e}"))?;

fn parse_okx_decimal(s: &str) -> Option<Decimal> {
    let s = s.trim();
    if s.is_empty() { return None; }
    s.parse::<Decimal>().ok()
}

match parse_funding_rate_msg(&msg, ts_init) {
    Ok(u) => emit(u),
    Err(e) => log::warn!("dropping funding rate update: {e}"),
}

When it happens

Trigger: A funding-rate websocket message (parsed via parse_funding_rate_msg or parse_funding_rate_msg_vec) carries a funding_rate string that is empty, non-numeric, or uses a format Decimal cannot parse (e.g. scientific notation edge cases or locale-formatted numbers).

Common situations: OKX sends an initial/placeholder snapshot with an empty fundingRate before the first computed value; API change in the funding-rate channel payload; intercepting messages from the wrong channel so unrelated strings land in the funding_rate field; proxy/CDN mangling the payload.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

• Invalid funding_interval, cannot be negative
• Unsupported Deribit resolution: {resolution}
• Unknown order direction: {}
• Unknown trade direction: {}
• Unknown position currency '{pos_ccy}' for instrument {instru

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/fded485b605292ce. Report an issue: GitHub.