The Dow Jones Industrial Average jumped almost 1% yesterday, rising 106 points as both sides sought to bridge the yawning maw of the fiscal cliff. But there's plenty of time for more partisan politicking, and we'll likely see more gyrations as we saw yesterday, when the index started the day down well over 100 points, but rallied to end the day strong.

Although there were a few stocks that actually fell on the day -- Boeing, Cisco, and DuPont were all off less than 1% -- it was a good day for the Dow and Wal-Mart jumped 1.5% as its Thanksgiving weekend sales proved stronger than most thought they would.

Yet while I expect the exuberance will be fleeting and we'll see greater volatility in the markets, some companies managed to do even better than the Dow, even rising by double-digit percentages.

Company

% Gain

Green Mountain Coffee Roasters (NASDAQ:GMCR)

27.3%

Knight Capital Group (NYSE:KCG)

15.2%

Groupon (NASDAQ:GRPN)

11.6%

Yet resist the urge to high-five everyone in the cubicles next to you. Smart investors won't celebrate until they know why their stock surged, because without a fundamental basis for the bounce, these stocks could just as quickly make the return trip down.

Who's got short shorts?
Better-than-expected earnings and guidance sent Green Mountain Coffee Roasters higher as it benefited from an extra week of selling in the quarter. Revenues jumped 33% to $947 million in 14 weeks compared to $712 million in 13 weeks last year. While the results were stronger than anticipated, the surge was also no doubt the result of a short squeeze.

Green Mountain's short interest ratio was on the rise, up 36% in the latest two-week reporting period to 16.7 days, and more than double where it was a month ago. Shorts have been expecting the expiration of patents to weigh more heavily on results than they apparently have. I'm thinking they were just a little early. With new machines out from Starbucks to Wal-Mart and discount coffee pods on the shelves of Kroger and Safeway, we'll likely see the new competition take its toll in the coming quarters.

Although I've been a longtime bear on Green Mountain Coffee Roasters, I've also said it would continue to dominate the world of single-cup coffee brewing. Its Keurig machine is the best-known brand and it has millions of loyal fans who will remain so. A National Coffee Association study said that 7% of respondents owned a single-cup brewer and that the number was growing by 1% a year. It's just that I don't think we can look to Green Mountain to be a growth stock anymore and its performance will lag the indexes over time. But tell me in the comments section below if you disagree that the coffee specialist's stock will ultimately be as stale as day-old joe.

A white knight
Just a few months ago it appeared market maker Knight Capital Group was doomed to die after a software glitch caused it to suffer $440 million in trading losses and halted the trading of its stock. Customers who couldn't fill orders quickly bailed on it, and though it secured a lifeline that allowed it to open its doors again, the future remained cloudy -- until it got a buyout offer. Several, actually.

Although the bids are said to be in the $3 to $3.50 range, management says it wants at least $4 for the business, but can beggars really be so choosy? When you're hanging by a thread, you really ought to be thankful anyone wants what's left. Yet even management's baseline bid is a long way down from the $10 a share it was trading at before the tumult, and investors can at least be thankful they'll be able to salvage something out of this debacle.

Down the rabbit hole
Like the Queen of Hearts in Alice in Wonderland, Groupon investors were charging around yesterday yelling "Off with his head!" They're referring, of course, to CEO Andrew Mason, who might soon find himself without a job.

Rumors are swirling that when it meets today, the board of directors will decide his fate and whether, like Google, it needs an adult to supervise the kids. Eric Schmidt was brought in to oversee the Romper Room that was the Googleplex, and some think it may be time Groupon got a chaperone too.

Investors seem to like the idea, as they boosted the daily-deal site's stock 12% higher, but I'm not convinced that's enough to change its direction. While the site has lost some 80% of its value since its IPO, Groupon still has no competitive moat to speak of, so what an overseer will do, I'm not sure. Let me know, though, whether you think Groupon will send Mason to the guillotine.

Rich Duprey owns shares of Cisco Systems. The Motley Fool owns shares of Google and Starbucks and has the following options: short JAN 2013 $47.00 puts on Starbucks. Motley Fool newsletter services recommend Green Mountain Coffee Roasters, Google, and Starbucks. 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 has a disclosure policy.