Perhaps people sell systems that end up working out. I don't know what aberration is and I haven't looked at it, but my guess is that it had a drawdown somehere along the line that would wipe most of its traders out. So even if it was profitable over a 10 year period, it was basically not workable. Not to mention possible slippage and accuracy of results issues. Further, it may have had most of its profits during that 1999-2001 period. I, like many, designed systems that were incredible during that run, but are less than worthless now.
But, maybe I'm wrong and I should start trading aberration immediately.
But, maybe I'm wrong and I should start trading aberration immediately.