What's the trick to make money in Vegas? Just keep playing to you get ahead.
Let's suppose you can bet $1, and get $2 with 48% probably, $0 with 52% probability.
First, bet $1. If you win, you're ahead $1. Quit.
If you lose, you're down $1, so bet $2. If you win, you're ahead $1. Quit.
If you lose, you're down $3, so bet $4. If you win, you're ahead $1. Quit.
And so on.
Your odds are 48% of being ahead after the first turn, 71% after the second turn, 82% after the third turn. By the sixth turn or so they're over 90%!
Wall Street, unlike Vegas, tends to give you positive expected returns. Nonetheless, I think a fallacy similar to the one contained in the above advice has plagued Wall Street repeatedly in the past couple of decades. The word "leverage" is a warning sign.