Legendary Manchester United manager Sir Alex Ferguson's decision to retire at the end of the season caught the world of football by surprise this week. But some investors were already shorting the stock and, for them, news of the Scot's departure was a chance to cash in.

Shares of the English club, which are traded under the MANU ticker on the New York Stock Exchange, fell nearly 5% in early Wednesday trading on concerns that Ferguson's departure could have a damaging impact on the company. The stock recovered most of its loss during the day, closing down 1.7%.