[Girchuck]

In poker, once the hand is played, you take a pot and move on.
The hand is gone forever. maybe you learn something, but otherwise, it has no relevance.
In the market, the stock stays on the market for a long time.
Perhaps you reasoned that the stock will be a loser in the next quarter, or next year, but whoever buys it doesn't care about the next year and thinks that in a longer time frame it will be a winner.
You could both be right in this case, and both of you could profit if you are both right.