"The turtle lives 'twixt plated decks
Which practically conceal its sex.
I think it clever of the turtle
In such a fix to be so fertile."
-- "The Turtle," by Ogden Nash, 1940

When earnings rebound from a severely depressed low, the speed of that bounce is apt to take Mr. Market by surprise.

Take for example analog semiconductor designer and Motley Fool Stock Advisor recommendation Linear Technology (Nasdaq: LLTC). Look up this stock in your favorite financial Web service right now, and you'll probably walk away thinking it's way too expensive: A sampling of the most popular finance sites puts Linear's price-to-earnings ratio somewhere between 26 and 29 times trailing earnings.

To put those figures into perspective, champion growth stock Apple (Nasdaq: AAPL) trades for 24 times trailing earnings and priceline.com (Nasdaq: PCLN) has a P/E of just 27. Many investors call those stocks too expensive despite their proven records of rapid earnings growth. So how could you justify Linear stock trading at such lofty levels?

Well, Linear reported earnings last night. Net income doubled year over year to $0.44 per share, moving Linear's true trailing P/E to a more reasonable 23 times trailing earnings. Assume that this quarter's results will be sustainable going forward and you get a forward P/E of only 17 times this run rate. In other words, Linear isn't nearly as expensive as a quick look at its P/E might imply. It's easy to deliver eye-popping growth figures and lower your P/E ratio when you're coming off an abnormally low bottom -- as Linear is doing.

CEO Lothar Maier said that sales are expected to grow again next quarter, following the third quarter's 21% sequential improvement and 55% annual growth to $311 million. Orders are strong across all geographies and end markets, and end-user demand is strong, too. Linear is an important supplier of components to Apple and other consumer electronics giants, so Linear will be all right as long as consumer demand is going strong.

Linear Technology may not be much of a household name, overshadowed by larger rivals like Texas Instruments (NYSE: TXN) and Analog Devices (NYSE: ADI), but the stock is highly respected by those who know it. It's a five-star CAPS stock with an impressive approval rating of 96% among more than 750 ratings -- and 98% among All-Star CAPS players.

I'm adding my own All-Star CAPS approval to that haul right now because Linear's stock looks undervalued relative to the rebound in this company's results. You can follow my footsteps (size 13, easy to track) and weigh in yourself in a couple of easy clicks. Like Ogden Nash's turtle, Linear is surprisingly fertile 'twixt the plated decks of obscurity and a depressed earnings history.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. Apple, Linear Technology, and priceline.com are Motley Fool Stock Advisor picks. Try any of our Foolish newsletters today, free for 30 days. You can check out Anders' holdings and a concise bio if you like, and our Foolish disclosure policy is again drinking deep from the prosodic well of National Poetry Month.