Buy-at-close-if-close-is-below-SMA-Low-3

CODE:

using WealthLab.Backtest;
using WealthLab.Core;
using WealthLab.Indicators;

namespace WealthScript1 
{
    public class MyStrategy : UserStrategyBase
    {
        //Initialize
        public override void Initialize(BarHistory bars)
        {
         smaLow = SMA.Series(bars.Low, 3);
         smaHigh = SMA.Series(bars.High, 3);
         PlotIndicator(smaLow);
         PlotIndicator(smaHigh);
         StartIndex = 4;
        }

        //Execute
        public override void Execute(BarHistory bars, int idx)
        {
         if (idx == bars.Count - 1)
            return;
            if (OpenPositions.Count == 0)
            {
                if (bars.Close[idx + 1] < smaLow[idx + 1])
               PlaceTrade(bars, TransactionType.Buy, OrderType.MarketClose);
            }
            else
            {
                if (bars.Close[idx + 1] > smaHigh[idx + 1])
               PlaceTrade(bars, TransactionType.Sell, OrderType.MarketClose);
            }
        }

      //private members
      private SMA smaHigh;
      private SMA smaLow;
    }
}