Fix bug

Author: konard

csharp/TraderBot/TradingService.cs

@@ -657,7 +657,7 @@ private bool IsTimeToBuy()
     private async Task<(decimal, decimal)> GetCashBalance(bool forceRemote = false)
     {
         var response = (await InvestApi.Operations.GetPositionsAsync(new PositionsRequest { AccountId = CurrentAccount.Id }));
-        var balanceFree = (decimal)response.Money.First(m => m.Currency == Settings.CashCurrency);
+        var balanceFree = response.Money.Any() ? (decimal)response.Money.First(m => m.Currency == Settings.CashCurrency) : 0;
         var balanceLocked = response.Blocked.Any() ? (decimal)response.Blocked.First(m => m.Currency == Settings.CashCurrency) : 0;
         Logger.LogInformation($"Local cash balance, {Settings.CashCurrency}: {CashBalanceFree} ({CashBalanceLocked} locked)");
         Logger.LogInformation($"Remote cash balance, {Settings.CashCurrency}: {balanceFree} ({balanceLocked} locked)");