- Hedge funds can be quant (i.e. computerised models) or non-quant (humans analysing and making judgement calls).

- Prop-trading shops or family offices do the same things as hedge funds, but are not open to the public, benefiting from less oversight or compliance requirement. Jane Street is an example, better (actually successful) examples are Renaissance Technologies and Soros Fund Management.

- Quant funds can be prop shops, hedge funds or mutual funds (or something in between like managed futures/CTA funds).