It’s simple. You are going to need collateral — BTC or ETH will do. Use this to borrow USDT from the open source money markets. Sell the USDT for BTC or ETH. You can double down by cycling this recursively and borrowing up some percentage of to your collateral if you wish to increase your leverage.

Meanwhile, you are paying 3-4% to whomever you are borrowing from. Addendum Meanwhile, you are probably funding an ecosystem something you are do not understand and against in the first place. :-)

Sell short USDTUSD on an exchange that supports margin trading.