The academic definition of shorting is to borrow someone else's asset such as stocks, sell it now and repay it later. So I assume that when I short the stocks, money is credited to my account from a stock exchange. This is what I learned from my finance textbook.
However, when I trade cryptocurrencies on Binance or Coinbase and short cryptocurrencies, no crypto currency exchanges give me money to my account. Only unrealized Profit and Loss changes in accordance with price changes. What I assumed was that if I short 1 BTC, a cryptocurrency exchange would give me about 60,000 USD, the price of 1 BTC. This never happens.
Can anyone fill in the gap between my understanding of shorting and the reality of it, please?
It seems like the textbook definition of short selling is "naked short selling", which allows you to short assets, even if you do not have money nor collateral. However, in reality, cryptocurrency exchanges only allows "covered short selling", in which collateral or deposit is needed to open short selling. Am I right on this point?