getSymbolCapital(exchangeName, symbol) {
    const capital = this.instances.symbols.find(
      instance =>
        instance.exchange === exchangeName && instance.symbol === symbol && _.get(instance, 'trade.capital', 0) > 0
    );

    if (capital) {
      return OrderCapital.createAsset(capital.trade.capital);
    }

    const capitalCurrency = this.instances.symbols.find(
      instance =>
        instance.exchange === exchangeName &&
        instance.symbol === symbol &&
        _.get(instance, 'trade.currency_capital', 0) > 0
    );

    if (capitalCurrency) {
      return OrderCapital.createCurrency(capitalCurrency.trade.currency_capital);
    }

    const balancePercent = this.instances.symbols.find(
      instance =>
        instance.exchange === exchangeName &&
        instance.symbol === symbol &&
        _.get(instance, 'trade.balance_percent', 0) > 0
    );

    if (balancePercent) {
      return OrderCapital.createBalance(balancePercent.trade.balance_percent);
    }

    return undefined;
  }
@param exchangeName string
@param symbol string
@returns OrderCapital