Here is an example that shows how to code rotational trading system with rebalancing. The system buys and shorts top 20 securities according to absolute value of positionscore (user definable – in this example we used 20 day rate-of-change) – each at 5% of equity then each day it rebalances existing positions to 5% if only the difference between current position value and “ideal” value is greater than 0.5% and bigger than one share.
Note that this code sample uses Custom Backtester interface that is documented here.
EnableRotationalTrading();
EachPosPercent = 5;
PositionScore = ROC( C, 20 );
PositionSize = -EachPosPercent;
SetOption("WorstRankHeld", 40 );
SetOption("MaxOpenPositions", 20 );
SetOption("UseCustomBacktestProc", True );
if( Status("action") == actionPortfolio )
{
bo = GetBacktesterObject();
bo.PreProcess(); // Initialize backtester
for(bar=0; bar < BarCount; bar++)
{
bo.ProcessTradeSignals( bar );
CurEquity = bo.Equity;
for( pos = bo.GetFirstOpenPos(); pos; pos = bo.GetNextOpenPos() )
{
posval = pos.GetPositionValue();
diff = posval - 0.01 * EachPosPercent * CurEquity;
price = pos.GetPrice( bar, "C" );
// rebalance only if difference between desired and
// current position value is greater than 0.5% of equity
// and greater than price of single share
if( diff != 0 AND
abs( diff ) > 0.005 * CurEquity AND
abs( diff ) > price )
{
bo.ScaleTrade( bar, pos.Symbol, diff < 0, price, abs( diff ) );
}
}
}
bo.PostProcess(); // Finalize backtester
Filed by Tomasz Janeczko at 2:32 pm under Custom Backtest
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