There is a sense of panic (not to mention a shift to unfiltereds from filtereds) coming out of the East Setauket lair of gazillions of teraflops in computing power. It appears one of the world's largest supercomputers keeps getting pantsed by 19 year old quants. Even as the S&P dropped almost 2% in October, and even though RIEF outperformed this performance by about 140 bps, investors apparently have had enough. With the magical line in the AUM sand of about $4 billion is likely to be crossed (in the wrong direction) very soon, your questions about the reasons behind Mr. Simons EOY retirement should be all laid to rest.
P.S. According to rumors Medallion not doing that hot in October either.