Quant trading guru Jim Simons is calling it a day, sort of.

The mathematician and cryptologist is famous in the investing community for bringing his analytical eye to the world of the stock exchange, creating both the quant trading revolution and a personal fortune now estimated at more than $22 billion. His has been a career of multifaceted success, and his innovations on Wall Street have influenced the strategies of two successive generations of traders.

Simons has stepped down as Chairman of Renaissance Technologies ahead of his 83th birthday next month. However, Simons remains involved as a board member.

On his way out, Simons staked new positions in two biotech stocks. Following Simons’ stock moves is a viable strategy for investors of all strips. To