Two Sigma, Renaissance Technologies possibly. Jane Street like the other reply mentioned

What about Bridge water and Hudson river trading

Bridgewater is not an HFT, they are a hedge fund.

That being said - Bridgewater are looking for more than just skills. Bridgewater is very heavy on meetings and those meetings being recorded. You can ace the skillset, but would be completely inadequate.

Their interview process is great. It's very honest and revealing. I don't fit the company and I made the decision at their campus interview, their opinion matched mine as well.

But, unlike most other companies, you are shown exactly what the company is. Which is very good.

If you can land an interview, you like them and get an offer - I hear that it's a pretty good place to work.

two sigma, de shaw, aqr, etc.

Citadel.

Jane Street is one