I attempted to create the Linear Long-Short Algo from the book Algorithmic Trading, Example 4.3. The strategy is to take an index of stocks and buy yesterdays losers and short yesterdays winners in proportion to how far the stocks are from the mean.
With Quantopian you're limited to 100 stocks, so the S&P 100 is used. (Minus GOOG, BRK.B, and WAG which cause problems). Trading daily.
Interestingly the algo performs surprisingly poorly and does not replicate the results described by Chan or by the original Khadhani and Lo paper. See if you can improve it!