Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of power systems maker Vicor (Nasdaq: VICR) short-circuited today, dropping as much as 13.2% on very heavy trading volume.

So what: It would be unfair to say that Vicor's fourth-quarter report disappointed analysts, because I can't find evidence of a single firm following this stock, and management doesn't do guidance. Still, it's objectively bad news when the book-to-bill ratio lands at 0.66, far below the kingmaking 1.0 benchmark.

Now what: Vicor's sales are accelerating and margins are blossoming across the board, so it's not all bad news. Including today's drop, the stock has climbed more than 65% over the last year and it's also one of the highest-yielding dividend payers in the construction industry. Power-chip rivals Vishay Intertechnology (NYSE: VSH) and Power-One (Nasdaq: PWER) are climbing higher and faster but don't reward investors with a dividend. They're also followed by Wall Street (though lightly so in the case of Vishay), making Vicor the true dark horse in this market.

Interested in more info on Vicor? Add it to your watchlist.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. The Fool owns shares of Power-One. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool is investors writing for investors.