🤡Some people naively (or unawarely) have difficulty understanding the technical dynamics on chain and exchanges. Centralized stablecoin issuers often perform "mint" and "burn" operations, simply because they move liquidity from one chain to another.
Stablecoin mint does NOT mean that the market must pump (in fact after a few hours there was yet another big dump of altcoins and this time also of BTC). 

If there are 50 billion USDC, there are 50 billion dollars somewhere. Issuers cannot issue stablecoins randomly to buy assets.
I read this also when Tether mints USDT through Bitfinex. 
These are routine operations to move liquidity (Tether and Bitfinex continuously mint/burn USDT between Ethereum mainnet and Tron).
Stablecoins from whales and institutions that instead arrive on exchanges, can equally have a dual (opposing) purpose:

1) Buy assets
2) Short

So be careful when reading bad information on Twitter!