Back是“支持”，wrong horse就是“错的马”，这个短语是什么意思呢？请看对话：

    A: The buying momentum is back. How’s your stock doing?

    B: The company has been losing money, and I am beginning to feel that I may have backed the wrong horse.

    A: Indeed. Counting on the price of a steel manufacturer to rise sharply is backing the wrong horse.

    Note: This idiom means to “support a person or thing that fails” or “guess wrongly or misjudge a future outcome.” People also say “betting on the wrong horse.” Transferred from wagering money on a horse that fails to win the race, a usage dating from the late 1600s, this term is widely applied to elections and other situations of uncertain outcome.