Thanks this was perfect and was similar to what I guessed the tweets were about. This is how the government / banking industry / whoever is able to manipulate the price of any asset. The asset is traded on exchanges which can add any amount of supply that they want because they don't actually have to have the real asset backing it.

The same thing can and likely is done for bitcoin and other cryptocurrencies. There may be a max of 21M bitcoin but exchanges can add as much supply as they want to dump onto the market to suppress the price and no one will ever know unless a majority is attempted to be withdrawn from the exchange, which will never really happen.

This is why the "proof of keys" movement is so important.