There's also people C and D who sold to A and bought from B... So looking at it from a whole is different from just the buyer and seller. There's a chain. I a

There's also people C and D who sold to A and bought from B... So looking at it from a whole is different from just the buyer and seller. There's a chain. I agree it's not a zero sum as stocks can rise independently of just market activity if the company is doing well.