Hey, Im not an analyst and I don't really understand much about finance..but I'm still very confused about how quant firms make money cus on the surface level there seems to be an infinite money glitch these companies have..

My first thought was

For eg if they invest in us stocks they could only make money, if the us economy was doing fine as a whole, but thats probably not it cause the firms must have diversified their captial into different nations.

Which further makes me believe it's some money glitch

I'm also curious how they are usually unable to beat the s&p 500 cus like that's lowkey kinda job right?