Quantitative analysis · Researcher

You build the statistical and machine learning models that Jane Street uses to price and trade financial instruments. A quantitative researcher looks for patterns in market data that say where a price should be or which way it is likely to move, then turns those patterns into models and trading strategies the firm runs with real money. Researchers, engineers and traders sit a few feet apart and work on the same problems, so what you build goes straight into the systems that trade.

The firm does not fix on one kind of model. Depending on the problem you might use a simple linear model, which draws a straight line through the data, or deep learning, which trains a large layered network to find patterns on its own. The choice is made by what fits the question, not by habit.