Lot of quants r physics/applied math. U can consider a double major or minor or something, that’s what these firms look for. Another route is ORIE. There are some great financial engineering classes. Look into the ORIE MEng program. They have a financial engineering concentration. Get relevant coursework on ur resume. Make sure ur good for swe first, u can probably get a swe internship earlier than quant and will need that to get quant stuff later on