主要讲了西蒙斯（Simons）个人经历。从小他就爱思考，并且在数学上展现了不俗的天赋。但是与普通数学家不同，他也很爱钱，不是他奢侈，而是喜欢金钱带给他的力量（他第一任老婆说：“Jim understood at an early age that money is power. He didn’t want people to have power over him.”）。拿到PhD后他先去哈佛教书，后来生活所迫并且觉得无聊就跑去IDA工作，专门破解苏联密文。这段经历对他影响很大：
However, their methods were never subjected to independent and thorough testing, and most of their rules arose from a mysterious combination of human pattern recognition and reasonable- sounding rules of thumb, raising questions about their efficacy.
1980年代华尔街招了大量的Quant，主要是做定价、风控，但1987年的股灾让他们名声变得很臭。这时候还有个叫Benoit Mandelbrot的教授号称金融市场遵循分形（fractal patterns）。这意味着市场有更多未知的风险，与Nassim Nicholas Taleb这种从交易员变成的畅销书作者观点一致（trader-turned-author这个词有点嘲讽）。Taleb认为未来的风险比大部分模型捕捉到的要多。因为这些原因，大众对自动化交易有着负面态度。
Medallion would employ a single trading model rather than maintain various models for different investments and market conditions, a style most quantitative firms would embrace. A collection of trading models was simpler and easier to pull off, Laufer acknowledged. But, he argued, a single model could draw on Straus’s vast trove of pricing ata, detecting correlations, opportunities, and other signals across various asset classes. Narrow, individual models, by contrast, can suffer from too little data.
Just as important, Laufer understood that a single, stable model based on some core assumptions about how prices and markets behave would make it easier to add new investments later on. They could even toss investments with relatively little trading data into the mix if they were deemed similar to other investments Medallion traded with lots of data.
于是他们重写了Frey的代码，把交易成本、杠杆、风险指标等所有限制都放到程序里，这个程序一小时几次地不断求解最优组合做出最佳决策，直接输出结果。这样不仅方便文艺复兴测试新信号，也可以把整个系统做成自适应的，像期货那边的程序一样给力。例如如果一个交易没有执行，他会立刻重新计算均衡组合，调整持仓。最终他们使用50万行的程序替代了Frey几万行的程序。这个程序很成功，在长达十年的时间里，文艺复兴都是使用这个基于因子的均值回归模型。他们的秘诀是打败人类的不理性（“We make money from the reactions people have to price moves.”）。
This test code appeared to use a figure from back in 1991 that was roughly half the current number. Mercer had written it as a static figure, rather than as a variable that updated with each move in the market.