If you pick 0.25% and I pick 1%, then I make (or lose) 4 times as much as you. Simple as that.
It's not as simple as that though.
If you both invest 100 BTC, and a whale constantly bets to win the max profit, and loses, then the 1% guy wins more than 4 times that of the 0.25% guy:
After 100 or so whale losses, the 1% guy's profit is almost 6 times that of the 0.25% guy. His share of the bankroll keeps increasing relative to the more timid guy.
The converse is also true. If the whale wins, then the 1% guy loses less than 4 times as much as the 0.25% guy, and after around 100 whale wins has lost around 3 times as much as the 0.25% guy. His share of the bankroll keeps decreasing relative to the more timid guy.