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 memory module and solid-state storage mogul STEC (Nasdaq: STEC) fell as much as 10% below Monday's closing price today.

So what: Head-to-head rival Netlist (Nasdaq: NLST) just reported a weak third quarter, and then one of the two analysts following that company downgraded it. That was enough to send STEC tumbling as well.

Now what: I'm not sure it's fair to punish STEC for the faults of Netlist, which is a much smaller company and far less mature. STEC's business model appears to be firing on most of its cylinders these days, and the stock should recover from this largely baseless bump before too long. That said, last night's closing price was 47% above three-month lows set in August, and when end-market uncertainty rears its ugly head, nervous investors may be moved to take some profits off the table.

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