Not afraid of winning many trades, but afraid of getting emotional and losing a single trade. When you get emotional and lose a trade, you might only lose 100 units of oil, but your emotional trading could cause you to lose your entire account balance. Because you lost that 100, you want to make it back, so you'll take larger positions, trade more frequently. Of course, there's still a chance you'll win back the floating loss or even make a profit. However, this pattern is unsustainable because it only leads to zero. In the end, it results in bigger and bigger losses, until there's no capital left to go all-in, and you lose your money.