A lot can change in a year. And as the following list of stocks shows, some analysts have learned that the hard way.
A comparison of year-ago price targets to current stock prices shows that for 10 nondeal stocks in the S&P 500, analysts missed the mark by more than 60 percent. In some cases, the analysts turned out to be too optimistic, such as when it comes to Chesapeake Energy. More often, the analysts undershot, missing a huge move in Skyworks Solutions, for instance.
A year ago, the average price target on broadband connectivity company Skyworks was $52.18, according to FactSet. Now the stock is trading well above $100.
Alex Gauna of JMP Securities is one analyst who was targeting just $50 on the stock a year ago, albeit with a "market outperform" rating. Gauna, who has raised his price target on the stock six times in the past year, told CNBC on Monday that the wireless connectivity story is far from over, so Skyworks continues to have one of the "longest runways" out there.
If that's the theme for stocks that have impressed, the theme for disappointments is even more predictable: energy. Chesapeake and Transocean are each trading at about a third of the prices that analysts had been looking for a year ago.
Using a standard measure of percentage error, the 10 stocks that analysts got the most wrong follow. (Hospira, Humana and Cigna, which have surged on deal news, are excluded.)