Maybe they use it to something or it can be also because of the security matters..
IF you have a 'big' 'blooming' Satoshi era type wallet and just move, say 100,000,000 USD of BTC to Coinbase and let such sit...folk 'freak out' if they find
such as on 'whale tracker' and 'assume' you are going to sell...then you sit back and simply move it off without selling and buy the dip that you caused...
this only works if you have one big fricking wallet IMHO of major market shaking noteworthiness. (Ah, I could have been 'so evil' and played this game
if I'd only found out about BTC in Jan of 2009 (took down like 5 towers of major bbs game server that same month and year... I woulda been primed...loaded and set..sigh
....instead of 2013.)