You’re seeing it backwards. Theoretically, derivatives “derive” their price from cash market. Practically though, derivative volume is 400x that of cash volume3 and in a highly rigged environment, derivatives move before cash 12. So, stocks aren’t bought at 26000 because the stocks are cheap, but because whales decided to move the index from 26k - that’s what you call price action.
Only one reason. if it acts as a support, it’s because the whales are purchasing stocks to move the index.