
The S&P 500 Is the World’s Largest Momentum Strategy - fludlight
http://awealthofcommonsense.com/2016/05/the-sp-500-is-the-worlds-largest-momentum-strategy/
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totalZero
>You would assume that half of all stocks would outperform a market index
while the other half would underperform.

Why would you assume that? The probability space isn't even symmetrical.
Stocks can't drop more than 100%. Not to mention that prices tend to grind
upwards, but crash downwards, whereby mathematically the only way it works out
is if you have a skewed distribution. Even the most naive investor would have
a hard time justifying a "mean = median" assumption.

