2 ms·
This is actually an awesome illustration of why a lot of famous results in academic finance were wrong in the 70s and 80s. Returns don't average, they multiply.
by yellowstuff 7y ago
This is actually an awesome illustration of why a lot of famous results in academic finance were wrong in the 70s and 80s. Returns don't average, they multiply. If you get HHTT or TTHH you're in terrible shape:
2.25 * .36 = .36 * 2.25 = .81
You started with $1 and now have 81 cents. I recently learned that a lot of early computer-era academic finance actually made the same error of averaging returns, as described in Finding Alpha:
http://falkenblog.blogspot.com/2016/08/finding-alpha-pdf.html http://falkenblog.blogspot.com/2016/08/finding-alpha-pdf.htm...