freqtrade/freqtrade · error · ValueError

Unknown rounding_mode {rounding_mode}

Error message

Unknown rounding_mode {rounding_mode}

What it means

ValueError raised in price_to_precision when precisionMode is DECIMAL_PLACES but rounding_mode is neither ROUND_UP nor ROUND_DOWN. The function only supports those two rounding modes in the decimal-places branch.

Source

Thrown at freqtrade/exchange/exchange_utils.py:360

            precision = FtPrecise(price_precision)
            price_str = FtPrecise(price)
            missing = price_str % precision
            if not missing == FtPrecise("0"):
                if rounding_mode == ROUND_UP:
                    res = price_str - missing + precision
                elif rounding_mode == ROUND_DOWN:
                    res = price_str - missing
                return round(float(str(res)), 14)
            return price
        elif precisionMode == DECIMAL_PLACES:
            ndigits = round(price_precision)
            ticks = price * (10**ndigits)
            if rounding_mode == ROUND_UP:
                return ceil(ticks) / (10**ndigits)
            if rounding_mode == ROUND_DOWN:
                return floor(ticks) / (10**ndigits)

            raise ValueError(f"Unknown rounding_mode {rounding_mode}")
        elif precisionMode == SIGNIFICANT_DIGITS:
            if rounding_mode in (ROUND_UP, ROUND_DOWN):
                return __price_to_precision_significant_digits(
                    price, price_precision, rounding_mode=rounding_mode
                )

        raise ValueError(f"Unknown precisionMode {precisionMode}")
    return price

View on GitHub (pinned to 1c8edfe4d1)

Solutions

1. Pass freqtrade.exchange.exchange_utils ROUND_UP or ROUND_DOWN explicitly when calling price_to_precision
2. If you need truncation toward zero, compute the side yourself and map it to ROUND_UP/ROUND_DOWN before calling
3. Check the exchange's markets precisionMode via ccxt (market['precisionMode']) to understand which branch executes

Example fix

# before
price = price_to_precision(pair, price, 8, rounding_mode=some_mode)
# after
from freqtrade.exchange.exchange_utils import ROUND_UP, ROUND_DOWN
rounding = ROUND_UP if side == 'buy' else ROUND_DOWN
price = price_to_precision(pair, price, 8, rounding_mode=rounding)

from freqtrade.exchange.exchange_utils import ROUND_UP, ROUND_DOWN
assert rounding_mode in (ROUND_UP, ROUND_DOWN), f'bad rounding_mode: {rounding_mode}'

try:
    p = price_to_precision(pair, price, precision, rounding_mode=rounding)
except ValueError as e:
    raise ConfigurationError(str(e)) from e

When it happens

Trigger: Calling price_to_precision (or amount/price precision paths that delegate to it) with a rounding_mode constant other than ROUND_UP/ROUND_DOWN while the exchange's precision mode is DECIMAL_PLACES (e.g. passing ROUND_NEAREST or an arbitrary int).

Common situations: Custom strategy or exchange subclass code passing an unsupported rounding mode; importing rounding constants from the wrong module so values collide; new exchange integration with mismatched precision semantics.

Related errors

• Could not create {ordertype} {side} order on market {pair}.
• Unknown precisionMode {precisionMode}
• `{new_path}` already exists. Please choose another Strategy
• Market exit orders require exit_pricing.price_side = "other"
• The config stoploss needs to be different from 0 to avoid pr

AI-assisted analysis of freqtrade/freqtrade@1c8edfe4d1 (2026-08-15). Data as JSON: /api/errors/5c0bd63218a5759f. Report an issue: GitHub.