This "survivorship bias" ignores the many traders whose losses from using charts drive them out of the market.
You've got survivorship bias taking out bad records and then you've got backfill bias adding good records.
So the survivorship bias and the backfill bias would be much, much more of a problem in the hedge fund world.
Now,more than 130 managers failed because, in addition to survivorship bias, there's something called backfill bias.
Looking at this particular group, he estimated survivorship bias to be 4.4% per year and backfill bias to be 7.3% per year.
