Well, for starters, he wasn't a friend, he was someone I knew on the forum as well as I know you now, which is almost nothing. But no, I don't think luck changes. He proved to be good at trades but making too many usually ends in screw ups like that one, that's why I was warning you about your trades on Betfury. Normally when you win it's best to take a break, we see too many stories on the forum where someone was winning, either in bets or trades, couldn't stop betting/trading and ended up losing everything. Enjoy the profits, you'll have plenty of time in the future to lose.
Nothing beats the adrenaline rush from the gains in our investments and wins in betting, but every time someone starts getting too excited, things start going wrong. That's why we must set a strategy from the beginning and stick to it strictly. No matter what happens.
Buy the dip
sell the pump
Step downs
Ladder ups
...
You're right, that's exactly what I was telling my friend earlier today: don't buy BTC with all the money you have, split it into parts. For example:
If I earn $500 in a month, divide that amount by 4. That way, I can buy every week of that month, like this:
Week 1 to Week 4: Buy $125 each week.
By doing it this way, besides always having money in fiat when you need it, even if BTC depreciates, once it goes up, you make a profit in one go.