MT5 Market order open/close
Sample below shows how to open and close market order with MT5 API.
var api = new MT5API("45.76.194.231:443", 7371, "mt5api"); api.OnConnectStatus += ConnectionStatus; api.Connect(); string symbol = "EURUSD"; api.Subscribe(symbol); while (api.GetQuote(symbol) == null)     Thread.Sleep(1); var quote = api.GetQuote(symbol); var o = api.OrderSend(symbol, 100, quote.Ask, OrderType.Buy, 0, 0, 0, null, 0); Console.WriteLine(o.Ticket); api.OrderClose(o.Ticket, o.Symbol, quote.Bid, o.Volume, o.OrderType); Console.WriteLine("Closed"); Console.ReadKey();