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 Activision Blizzard (Nasdaq: ATVI) took a beating after the company announced the break-up of the Guitar Hero franchise and a disappointing first-quarter outlook. Shares dropped 11%.

So what: After excluding some items, Activision Blizzard told investors to expect first-quarter earnings of $0.07 per share. Analysts were expecting $0.10 a share. The company also announced plans to cut 500 jobs. (Including more than a few of its former rockers, presumably.)

Now what: There's no spinning this record: The news stinks, especially when you consider the stellar numbers put up by gaming peer Take-Two Interactive (Nasdaq: TTWO) this week.

Take-Two, home of the Grand Theft Auto franchise and the more recent hit Red Dead Redemption, booked $0.52 in per-share earnings on $334 million in revenue. Both results easily beat estimates. By contrast, Activision Blizzard reported a narrower Q4 loss on lower revenue.

Bulls will argue that Activision ended its year producing more than $1 billion in free cash flow. They're right; that is impressive. But with lower guidance and the loss of what had been a great franchise, it's tough to blame the bears for biting.

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

Activision Blizzard is a Motley Fool Stock Advisor selection. Take-Two Interactive is a Motley Fool Rule Breakersrecommendation. Motley Fool Options has recommended subscribers open a synthetic long position in Activision Blizzard. Try any of our Foolish newsletter services free for 30 days.

Fool contributor Tim Beyersis a member of the Motley Fool Rule Breakers stock-picking team. He didn't own shares in any of the companies mentioned in this article at the time of publication. Check out Tim's portfolio holdings and Foolish writings, or connect with him on Twitter as @milehighfool. You can also get his insights delivered directly to your RSS reader. 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 owns shares of Activision Blizzard and Take-Two Interactive and is also on Twitter as @TheMotleyFool. Its disclosure policy is at least 10% better than other disclosure policies.