Одновременная отправка 2-х заявок

//если покупаем 1-й инструмент и продаем 2-й
if (условие входа)
{
log("Вход 1-й покупаем, 2-й продаем");
noga1_buy(0,0);
noga2_sell(0,0);
}

        void noga1_buy(int pos, decimal price)
        {
            if (pos == 0) pos = 1;
            if (price == 0) price = _ins1.BestAsk.Price;

            var order1 = new Order
            {
                Portfolio = _portfolio,
                Price = price,
                Security = _ins1,
                Volume = unit1 * pos,
                Direction = OrderDirections.Buy,
            };
            log("покупаем 1-ю ногу " + order1.TransactionId + " по цене" + order1.Price + " int1_pos=" + int1_pos + " int2_pos=" + int2_pos + " delta_theory=" + delta_theory + " " + order1.Direction + " delta_real=" + delta_real);

            Trader.RegisterOrder(order1);
            log("Заявка отправлена");
        }



        void noga2_sell(int pos, decimal price)
        {
            if (pos == 0) pos = 1;
            if (price == 0) price = _ins2.BestBid.Price;

            var order2 = new Order
            {
                Portfolio = _portfolio,
                Price = price,
                Security = _ins2,
                Volume = unit2 * pos,
                Direction = OrderDirections.Sell,
            };
            log("продаем 2-ю ногу " + order2.TransactionId + " по цене" + order2.Price + " int1_pos=" + int1_pos + " int2_pos=" + int2_pos + " delta_theory=" + delta_theory + " " + order2.Direction + " delta_real=" + delta_real);

            Trader.RegisterOrder(order2);
            log("Заявка отправлена");
        }


        void log(string s)
        {
            String current_time_str = DateTime.Now.ToString("HH:mm:ss.fff");
            textBox1.AppendText(current_time_str + " " + s + Environment.NewLine);
        }