In prediction markets or derivatives trading, the most common mistake is failing to set a take-profit order in advance.

It sounds simple, but it's really difficult to do. I've encountered similar situations before—confident about a certain direction, only for the situation to reverse at a critical moment. For example, in a certain game, I thought the big ball odds were safe, but in the final stages, a sudden change occurred, and the originally touched target was overturned or disallowed. And at this chaotic moment, someone was already aggressively closing out the opponent's positions, making a huge profit.

As for me? Too lazy or simply reacting too slowly, I went from profit to zero.

A painful lesson shows: market prediction risks accumulate in the details—end-of-day volatility, rule changes, liquidity drying up—any one of these can reverse the situation. Instead of betting on a perfect move at the last moment, it's better to exit decisively when profits are available. Placing a sell order in advance may seem conservative, but it's actually the best way to hedge against uncertainty.