In Back to the Future II, Biff Tannen, the jock-thug from the first movie, gives a sports almanac to his teenage self, allowing young Biff to bet on sports with 100% accuracy. By 1985, Biff is rich beyond imagination. Let's stop there and ignore all the horrific things that accompany the wealth -- death, deceit, destruction, other "D" words that are also bad. As an investor, don't you wish you had a newspaper from 2050, every now and then?

Today's results from Under Armour (NYSE:UAA) would be a perfect chance to make bank. The stock is up more than 20% at midday. Actually, it seems like you might just sell the DeLorean.

Under Armour grows like kudzu
Under Armour's pop came from an incredible increase in earnings per share. Analysts expected the company to hit $0.53 per share -- it turned in $0.59. That was a 27% increase over the previous year and it came out of nowhere.

Well, that's not entirely true. Under Armour had a crazy-good year, with quarterly earnings per share rising between 26% and 160% in each of the prior two quarters. For the full year, earnings per share were up 24%. Biff -- if he hadn't already sold the DeLorean -- would be rich.

Recently, the company has had a series of announcements setting it up for a strong 2014 as well. New marketing partnerships, new spokespeople, and big-name teams have all helped build a platform for the year. In addition to U.S. sales, Under Armour is setting up for international growth. This year, it's announced a tie-in with Colo-Colo, an incredibly successful Chilean football -- U.S. soccer -- club.

Think of the exposure Biff could have had if he was able to make big international bets.

The success of 2013 puts Under Armour much further down the path to its 2016 goal of $4 billion in revenue. Under Armour forecasts between $2.84 billion and $2.87 billion in 2014, an increase of more than 20%.

The road ahead
Under Armour's success still pales in comparison to the size of Nike's empire. Nike generated $6.4 billion in revenue in the last quarter alone. While Under Armour is still earning 94% of its revenue in North America, Nike is international like Esperanto. The company made more than half of its revenue internationally.

Under Armour's advantage is speed of growth. That comes at an impressive premium right now, with the stock trading well more than 70 times the company's last 12 months of earnings. Nike is sitting at just 25 times its past year.

As a result, now might not be the best "buying opportunity" for Under Armour -- unless you are very, very confident in its abilities. Hopefully, the company will have a pullback sometime this year and offer investors a better in. There's still a lot of good news ahead for Under Armour, and it would be nice to benefit.