It seems an understatement to say BlackBerry (NYSE:BB) shareholders have endured one heck of a roller-coaster ride this week.

First, shortly before the market close on Wednesday, shares of the jumped nearly 30% after Reuters reported Samsung (OTC:SSNLF) had made an offer to buy the beleaguered smartphone maker.

What goes up ...
Specifically, Reuters cited a "person familiar with the situation" as saying executives from both companies met last week. Reuters also said it has seen documents outlining Samsung's proposal with an initial per share offer in the range of $13.35 to $15.49, the high end of which indicated an enterprise value of roughly $7.5 billion for BlackBerry -- representing a 60% premium over the company's trading price earlier in the day.

At first, the offer seemed to make sense. While BlackBerry is obviously struggling to sell its handsets -- with its share of the U.S. smartphone market, for example, effectively falling to zero early last year as Samsung and Apple continued to dominate -- the two companies announced a new partnership almost exactly two months ago to integrate BlackBerry's market-leading BES12 software into Samsung's KNOX security system on Android. If Samsung could acquire BlackBerry's patents and enterprise software expertise, it could go a long way toward helping the South Korean conglomerate seize the enormous market for mobile business solutions.

... must come down?
On Thursday, however, BlackBerry's stock plunged 20% after the company issued a press release insisting "BlackBerry has not engaged in discussions with Samsung with respect to any possible offer to purchase BlackBerry." Then, in a likely attempt to circumvent further media inquiries, it added that "BlackBerry's policy is not to comment on rumors or speculation, and accordingly it does not intend to comment further." 

Samsung, for its part, called the Reuters report "groundless" in an email to Bloomberg.

End of story, right?

Not so fast
The latest action begs this question: Why didn't BlackBerry stock immediately give up all of its newfound gains in Thursday's trading? As of this writing, BlackBerry stock is hovering around 5% higher than it stood just prior to the Reuters report -- and that's despite the broader Nasdaq Composite index falling more than 1% today.

First, note that Reuters is sticking by its original report despite the denials from both companies. And Reuters isn't exactly known for haphazardly jumping to conclusions, especially when they involve actual documents the news service claims to have seen.

Next, while Samsung's message to Bloomberg was pretty succinct, the vague verbiage in BlackBerry's response does not deny such an offer exists. Rather, BlackBerry simply claims it hasn't "engaged in discussions with Samsung" regarding "any possible offer."

BlackBerry stock's recently elevated state could also be a byproduct of drawing attention to management's initiatives to create even greater shareholder value through services. Shortly after Reuters' first report, for example, The Globe and Mail newspaper published a separate piece citing "sources close to the company" who say BlackBerry has "shunned a handful of potential buyers in recent months, [...] some of which value the company at more than $7 billion." To explain its stance, The Globe and Mail said, BlackBerry's board believes the prospective bids fall short of the company's potential value.

That said, BlackBerry shareholders should not bet on an acquisition as a serious part of their investment thesis. To the contrary, if an acquisition does happen, it will likely occur after BlackBerry shows more tangible progress toward achieving its goals and penetrating its target markets. And make no mistake: that could be a tall order with the likes of Apple and IBM chasing the same customers.

But if BlackBerry has indeed shunned a number of suitors, and if its technology truly does have the potential to dominate the fast-growing enterprise mobility market -- which market researcher Radicati Group recently estimated will grow at an annualized rate north of 40% for the next several years -- I wouldn't be the least bit surprised if at least one of those potential acquirers eventually makes an offer BlackBerry deems worthy of its value.