The most important in Gambling and Investing is Money Management, otherwise said 'How you manage your Bankroll.'
Proctecting your capital.
No Bankroll = no Money
No Money = no opportunities to make Money
Since you should never "play" with Money.
The 5% Money Management Rule
Gamble no more than 5% of your Bankroll.
I can make 20 Bets with my personnal Bankroll.
It isn't dramatic if I lose a few bets in a row.
I have the same philosophy for investing in the stock market.
In the long-run,
Discipline is better than good picking.
Since you can't always pick the winner.
Nothing is 100% safe.
Nothing is 100% sure.
Not even fixed fights and inside trading.
Everything is possible!
So you should NEVER dedicate more than 5% of your Bankroll / Capital on a single bet, investment or poker game.