As the title says !
Can i get the people attentions to this question please ?
"Do bitcoin casinos have that power to make changes in the price of bitcoin ??"
no, they have no such power to do this.
bitcoin casinos are simply users of bitcoin with small amount of bitcoin compared to big players.
they don't even have enough bitcoin to be considered whales.
besides casinos are not in trading scene to be able to do anything about the price, the owner of one or two may do some trading on the side but that doesn't make casinos traders!