You get only 250k. Anything beyond that is not insured by FDIC ! Lot of startups and Venture capitalists put money in SVB. That is much higher than 250k !
It actually depends on the setup. Some entities do sweeps into multiple banks, theoretically allowing a higher than 250k limit. I'm not sure if Robinhood still does that or not, they've had multiple 'cash' offerings and I haven't kept up.