using System;

using System.Collections.Generic;

​

public class Program {

    public static void Main() {

        var trade = new Trading();

        trade.Trades.Add(new Trade() {Tid = 1, Date = DateTime.Now, Price = 100M, Amount = 10M, Type = "um"});

        trade.Trades.Add(new Trade() { Tid = 2, Date = DateTime.Now, Price = 200M, Amount = 20M, Type = "dois"});

    }

}

​

public interface ITrade {

    DateTime Date { get; set; }

    decimal Price { get; set; }

    decimal Amount { get; set; }

    string Type { get; set; }

}

​

interface ITrades {

    List<ITrade> Trades { get; set; }

}

​

public class Trade : ITrade {

    public int Tid { get; set; }

    public DateTime Date { get; set; }

    public decimal Price { get; set; }

    public decimal Amount { get; set; }

    public string Type { get; set; }

}

​

public class Trading {

    public List<ITrade> Trades { get; set; } = new List<ITrade>();

}