In the world of finance, these are people with science and math degrees who work in the finance field building highly advanced quantitative finance models. These models help banking, insurance and investment firms to price financial instruments.

If an investment firm hires a PhD student with a background in theoretical physics to create a model that prices futures and options, that person would be considered a "rocket scientist" by the traders in the investment firm because of the complexity and skill required to create these models that help traders of futures and options.