But i think lot of money is coming from LTC BCH recent pumps and BSV drama
based on what i have seen, majority of traders trade altcoins with bitcoin not with fiat. which means when they dump that altcoin they are dumping it in its bitcoin market (in this case for example they sell it in BSV/BTC market) which means "money "is not coming in bitcoin, people are just getting their bitcoins back after a loss.
even if they sell their altcoins for profit they are still selling it for bitcoin not fiat and their profit will be in bitcoin which either goes to their cold storage or goes into the next coin getting pumped.
Its much more complicated. When you sell altcoin for bitcoin you are dropping alt/btc price. That decrease calculated alt/$ price while alt/$ price on market remains constant, thats bring opportunity for arbitrage traders to do this sequence:
Buy bitcoin with $
Buy altcoin for bitcoin
Sell altcoin for $
buy bitcoin with $
continue... until there is no price difference.
Therefore, even when you dump altcoin into bitcoin you are in fact boosting bitcoin price. Size of that depends on how big USDT market is (especially order book).
Your sentence is true only on those coins that are not nominated in $ at all.
You can see interesting stats on
https://www.bitfinex.com/ usd and usdt if you click on usdt it looks like usdt are moving to eth
That does not mean anything. Especially now when bitfinex trading volume is marginal.