Yeah, let's just forget about the fact that every BTC up move was preceded by a fat Tether print since mid 2016. It's not Tether pumping, it's the people choosing bitcoin! derp
The amount of Tether just tracks the amount of money deposits, which are tokenized into USDT. Tether is just a small fraction of all the money entering exchanges.
Big crypto guy here; Tether is the bain of crypto. It is a centralized medium, that is accepted on centralized exchanges as fact with no audit on how much asset to coin ratio exists. Tether can print as many USDT as they want, buy up all the BTC on 100x leveraged long and no one would be the wiser. BTC's $700B market cap could be fairy dust and no one can know.
You say "can" but they "have"
No it does not. Tether dollars are not backed by real dollars or fairytale "customer deposits". They print Tethers and use them to pump bitcoin price to draw the attention of people like you (and me)