Exchanges and wallet maintenance scams

[kdn]

So in the last couple of days alone I have seen 2 cases of the same coin showing over 1000% difference in price across two different exchanges. Surprise Surprise, the lower priced exchange will let you buy the coin and transfer it out, but the higher priced exchange will not allow you to deposit the currency. "Wallet maintenance" or "deposits temporarily disabled"

do these exchange start disabling wallets when a coin starts pumping or what is going on there.. My guess is the exchange starts artificially pumping coins so their users start buying them, however they block outside funds coming in so they can keep the supply down and price up.