exchange ¤ Exchange implements Stable Exchanges¤ BackTest: Backtesting exchange MetaTrader: MetaTrader 5 live data and trading CCXT: CCXT CryptoCurrency live data and trading LetException ¤ Bases: Exception Base LetTrade exception LetOrderException ¤ Bases: LetException Base order exception LetOrderInvalidException ¤ Bases: LetOrderException Order place is invalid exception LetOrderValidateException ¤ Bases: LetOrderException Order attribute validate exception