Backtesting an Automated Buy-Sell Model Based on Smoothing Factors for SPY and SPXL Buy-Sell models are among my favorite analytical techniques because they simulate what self-directed and institutional traders do on a regular basis – namely, buy and sell financial securities. A buy-sell model can evaluate different strategies for profitably buying and selling securities. Over the past several months, this blog introduced and examined variations of a model for buying and selling financial securities based on exponentially smoothed security close prices. Simple exponential smoothing and exponential moving averages are two different approaches available for computing exponentially weighted historical values of an underlying set of time series values – like ticker prices. This post relies on securities prices smoothed by a combination of simple exponential smoothing and exponential moving averages. The model evaluated in the post compares unsmoothed historica...