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 Alliance Fiber Optic Products (UNKNOWN:AFOP.DL) jumped more than 10% early Thursday following a positive analyst note.

So what: Sidoti this morning initiated coverage on the company with a buy rating and a $28 per share price target. That represents a nearly 40% premium for investors who bought even after today's pop.

Now what: Even though Alliance Fiber Optic Products has risen nearly 70% from its February low -- a performance helped by its solid first-quarter results -- the stock still trades at a reasonable 3.9 times trailing 12-month sales, and 14.6 times next year's estimated earnings. I agree with Sidoti on this call, and can't blame the market for bidding up shares today.