so how do we know that crypto exchngers dont sell us the coins what they dont exisit?
The awaareness will also come first to the users. We are joining, signing up with reputable exchange. That means they will not risk thwir reputations and be transparent enough to show us if the coins are existing or not.
and how do we know those big funds who bought or pretinding to buy or sell some big ammounts of cryptocurrency `?
how do we know they dont lie us ?
I wonder where these doubtful questions came from? In the first place, why would a particular exchange exposed who brought big funds to their site? Perhaps you are aware of decentralized exchanges. If you are on doubt, just choose established and trusted crypto exchanges. Those who are chosen most of the traders so, you'll find out if it is worth to use that exchange or not.