If BTC goes up, the ALTS goes down.
This statement is 100% not true.
If BTC goes down, the ALTS goes down.
Again, totally false. Bordering on lie if the OP is try to deceive us.
What would happen if they control most of BTC?
People would abandon Bitcoin and move to Bitcoin Cash, Litecoin, Ripple, Monero, Dash, etc. That's the beauty of it, the bank can't control them all!