There was a Bloomberg article about this some years ago. Axcom was run by James Ax, and jointly owned by Ax & Simons. (Axcom was a 'trading advisor'. They ma

There was a Bloomberg article about this some years ago. Axcom was run by James Ax, and jointly owned by Ax & Simons. (Axcom was a 'trading advisor'. They made recommendations to Renaissance, which managed a fund based on these recommendations.) Ax was in essence hired by Simons to explore & develop quantitative trading ideas Simons & Baum had come up with while they were making more traditional trades. Berlekamp came along several years later, as a consultant. One can find claims that he developed a lot of RenTech's IP, but as far as I can tell these claims are sourced from Berlekamp himself. Since Berlekamp's own fund went out of business after a few years of operation, I'm inclined to dismiss these claims as marketing.