The professor who originally found stock prices of companies with the most-loved Super Bowl advertisements got a pop in the stock market is saying that effect is gone now. Shares of the companies with the top-ranked Super Bowl advertisements fell in the first days of trading following the big game in each of the past four years, according to Ken Kim, chief financial strategist of Eqis Capital and co-author of the 2008 paper “A test of the representatives bias effect on stock prices: A study of Super Bowl commercial likeability.” The fading away of the top Super Bowl ad pop is just another case of how the stock market’s efficiency works. Even if a trading advantage arises, it doesn’t take long for investors and the market to figure it out, trade on it — and eliminate the inefficiency. “I think the immediate positive effect that a highly liked Super Bowl commercial can have on their stock prices has simply worn off,” Kim told USA TODAY in an e-mail. If you don’t remember last year’s favorite Super Bowl ad, as measured by USA TODAY’s Ad Meter, it was the puppy from an adoption agency that chases to play with a Clydesdale horse. Despite the advertisement’s strong reception, shares of Anheuser-Busch’s stock (BUD) fell 1.6% on the Monday after the ad aired on Feb. 2. The same happened back in 2013, the year Anheuser-Busch won again with the Clydesdale being born. But again, the stock closed lower on Feb. 4, the first day of trading after the commercial aired. The same pattern of the shares of the USA TODAY Ad Meter Super Bowl winners falling on the first days of trading repeated in 2012 and 2011. It’s impossible to test the theory in 2010, since USA TODAY’s Ad Meter winner was Snickers, which is privately held. Part of the vanishing benefit of a popular Super Bowl ad has to do with the fact that it’s expected that either Anheuser-Busch or Pepsico (PEP) will win. One of those two firms has won the USA TODAY Ad Meter every year since 1994, with the exception of 2010. Investors simply anticipate it, Kim says. But fear not, companies prepared to pony up huge sums for 30-second spots in front of America on Super Bowl Sunday. Unexpected winners might gain. Take the example of RadioShack (RSH), which last year won fifth place with its commercial poking fun of its popularity in the 1980s. Shares of RadioShack gained 3.3% on the Monday following the 2014 Super Bowl. Keep in mind, though, that the pop was short-lived, and shares have since fallen 87% to 32 cents. Kim’s research was published originally in 2009. It was based on the previous 17 years of Super Bowl advertising popularity based on USA TODAY’s Ad Meter. Kim conjectured at the time that the pop in stock prices in popular commercials reflected many investors’ short-term thinking when it comes to picking stocks. But now it seems that Wall Street is doing what it does best – wiping out inefficiencies in the market. PERFORMANCE OF USA TODAY AD METER WINNERS’ STOCKS DAY FOLLOWING SUPER BOWLSuper BowlAd Meter winnerDay-after stock % ch.2014Anheuser-Busch-1.6%2013Anheuser-Busch-5%2012Pepsico (Doritos)-0.2%2011Pepsico (Doritos) – tie-0.3%2011Anheuser-Busch – tie1.3% Sources: S&P Capital IQ, USA TODAY research