Elwyn Berlekamp

American mathematician and Berkeley professor, co-inventor of the Berlekamp-Welch algorithm and co-author of Winning Ways for your Mathematical Plays, who briefly ran Renaissance Technologies and reoriented the Medallion Fund toward short-term trading.

Reoriented the Medallion Fund's strategy from long-term trend following to short-term mean reversion — the insight that short-term price inefficiencies were more predictable than long-term patterns — transforming the fund's performance in the late 1980s.