If you're a shareholder of Groupon (GRPN 8.21%), you'd better enjoy rollercoasters. After a dismal stock price performance since its IPO, Groupon's share price is up over 30% the past week. The jump in Groupon's value is great news for shareholders who've weathered the storm, but like any Fool, you need to know what's behind it to determine if it's sustainable, and whether you should add to your holdings.

There's no shortage of news coming from the Groupon camp this month, so it'd be natural to assume that somewhere in the recent press releases, SEC filings, or media reports, there's a tasty nugget, or three, responsible for the price jump. So, what's been making news over at Groupon? Unfortunately, not enough to account for its impressive performance of late.

Some recent news
The biggest news coming from CEO Andrew Mason and team was Groupon's Nov. 8 earnings announcement. As I pointed out in a recent article, the negativity -- and subsequent beat down of Groupon's share price following Q3 results -- was way overdone. In spite of hitting several financial milestones, and breaking even on earnings (versus a loss of $54 million in the year-ago period), Groupon stock was battered. Why? The usual: analysts cited "deal fatigue," a tidy little phrase Groupon aficionados have come to abhor.

More recently, Groupon announced free shipping, free returns, and the advent of a Groupon catalog for the upcoming holiday season. Those are neat concepts, and great for consumers of its relatively new Groupon Goods business line. To Groupon's credit, it was able to minimize marketing costs in Q3, shaving $30 million from selling, general, and administrative expenses compared to Q2. But whenever a company offers "free" anything, as an investor, my first thought is, "Yeah, but what about margins?"

The bigger news, at least in the long run, was the Nov. 14 announcement from Mason that Groupon was elevating its current SVP of global sales and operations, Kal Raman, to COO. No sense in revisiting the many issues involving Groupon senior management, particularly on the finance side of the house. But Raman's senior management background with the likes of eBay (NASDAQ: EBAY) and Amazon.com (AMZN -1.65%), among others, is certainly a positive for Groupon. Continuing to strengthen the management team should be, and is, high on Mason's to-do list, and Kaman is a step in the right direction.

On Nov. 19, Groupon shared more intriguing news: It opened a concept store in Hong Kong that allows customers to test the merchandise before buying, return items, and boasts over 4,000 square feet of floor space. This new approach will allow Groupon customers to bridge the gap between online and offline shopping. It's an idea worth watching, unless Groupon decides to transition its Groupon Goods unit into a traditional retailer. Mason knows better than that, right?

If you've gotten on the Groupon train in the last week, turns out you're not alone. Yet another intriguing tidbit was shared on Nov. 19: Tiger Global Management has taken a nearly 10% stake in Groupon. A recent filing with the SEC indicated Tiger bought 65 million shares, worth about $200 million as of the Nov. 19 closing price of $3.10. Not a reason to buy, but Tiger's an $8 billion hedge fund fairly well known for betting on tech-related turnaround stories, and Groupon certainly falls into that category.

Does any of this account for Groupon's pop?
Kaman's internal shift is a sound move to shore up the management team, Tiger Management betting on Groupon adds some credibility, and the steps to boost holiday revenues will bump revenue. That's a lot of interesting information from Groupon the past couple of weeks, unfortunately, none warrants Groupon's recent 30% jump in share price.

Competition for online coupon deals from Amazon.com's LivingSocial and AmazonLocal, Google's coupon alternative Google+, not to mention Facebook (META -10.56%) Coupons, isn't going away. Look for Facebook to focus on its online deals as it struggles to generate revenue streams -- much like Groupon in the past year. So, the jump in stock price isn't that Groupon's core business suddenly found itself alone in the market again.

So, why the good tidings? Following Groupon's Q3 earnings announcement, the stock was oversold, simple as that. At some point, investors will realize Groupon's efforts to expand its offerings, and minimize dependence on its core business, were spot on. Until then, Groupon remains an undervalued mid- to long-term growth opportunity.