Let's give example of you bought 100 BTC at 9000$ Price and the price went 9010$ in seconds then you sold, so your profit will be 1000$, may 500$ fees, but the another 500$ you made it profit in seconds!
Let's discuss at the point!
That you are lucky enough that after buying the market just pumps and that was amazing since you'll think of selling it right away unlike the others who just hold and wait for a little more. May you will find it good at this time but don't get surprised that at some time you will experiences losses.
To tell you friend that, there is no instant making money in Bitcoin investment, it was just a lucky and in perfect time that the situation goes like that. And you should also be aware about the volatility and that it changes everything in every minute. That if you come into the trading when the market is already high, you're certainly got not perfect and profitable but if you started buying during the bear season, that we could expect a big gain in the coming days.