If we compare the crypto assets market to the stocks markets in general, can Bitcoin be considerated as the equivalent of the dollar?
In the stock exchage we buy shares with dollars.
In the cryptocurrencies exchanges we buy tokens or coins with bitcoins(and other cryptocurrencies, Litecoins, etc).
To buy bitcoin you need to have fiat currency, if no how are you going to invest in other things, even if you want to mine these coins you need to invest a bigger capital, so what you really do is you are spending fiat currency every time and the only difference i see from stock exchanges and crypto currency market is that, stock exchanges does not operate round the clock and that is not the case with crypto currency market.