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 electronics retailer RadioShack (NYSE: RSH) fell 11% today after the company gave weak earnings guidance.

So what: Management expects to report fourth-quarter earnings of $0.50 to $0.54 per share, below estimates of $0.66 per share. To put icing on the cake, CEO Julian Day said he would be stepping down in May and CFO Jim Gooch will take over.

Now what: The management shakeup is helping push shares lower because analysts think it makes RadioShack less likely to be taken over in the short term, but the guidance is more concerning. The weaker results followed a similar hit at Best Buy (NYSE: BBY) last month as electronics retailers fight competition from big-box stores and online retailers. It doesn't look like electronics retailers will be able to fend off competition anytime soon, leaving this Fool to run for the hills today.

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

Fool contributor Travis Hoium does not have a position in any company mentioned. You can follow Travis on Twitter at @FlushDrawFool, check out his personal stock holdings or follow his CAPS picks at TMFFlushDraw.

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