Don’t expect to glean any market tips or trading secrets from James Simons, who steadfastly refuses to disclose the method behind his remarkable record in investing. Instead, listen to this mathematician, hedge fund manager and philanthropist sum up a remarkably varied and rich career, and offer some “guiding principles” distilled along the way. Simons drew a bead on studying math at MIT from an early age, which some acquaintances found surprising. As a 14-year-old, he was demoted in a temporary job from stockroom worker to floor-sweeper, because he “couldn’t remember where in hell everything went.” This switch suited him fine, since he had “lots of time to think.” When he told his employers he hoped to attend MIT, “they thought it was the funniest thing.” Ultimately, Simons had no choice about it: After Wesleyan recruited, then rejected him, there was only MIT. “I was destined for this place,” he says.  The idea of a math career was “clinched” for Simons after a typical late night of poker and sandwiches with MIT classmates. At 1 a.m. in a Brookline restaurant, Simons saw MIT math legends Isadore Singer and Warren Ambrose “doing math over coffee and cigarettes,” which he “thought was the coolest thing.” After a motor scooter trip to Bogota with Colombian friends — in whose business he fatefully invested -- Simons leapt into the math phase of his career, writing a famous Ph.D. thesis, teaching at MIT, solving prickly geometry problems and helping build bridges between math and physics. During this phase, he managed to get fired as a cryptanalyst at a Defense Department think tank, after criticizing the pro-Vietnam War stance of his boss, General Maxwell Taylor. While at Stony Brook’s math department, Simons “got really stuck, very frustrated,” trying “to prove a certain number was irrational.” Meanwhile, he had begun investing dividends generated by his South American business venture and “found out I was not bad at it.” In 1978 at age 38, with 20 ...