Wall Street was pretty excited about the prospect of Samsung buying BlackBerry when Reuters reported talks between the two last month. The Canadian smartphone maker's stock surged to its biggest single-day gain in years, according to CNBC, only to come back down to Earth after both companies denied any acquisition deal was in the works. But now the US Securities and Exchange Commission (and its Canadian counterpart) are investigating suspicious trading activity that — perhaps too conveniently — coincided with the big rumor.

The concern is that someone fed information to Reuters for the sole purpose of making a killing on the stock jump. According to CNBC's sources, one transaction the SEC is focused on occurred at 12:06PM (well ahead of the headline-making Reuters report) and potentially could have allowed its buyer to "make a profit of $490,000 on a $20,000 investment." At this point, CNBC says it's unclear whether the buyer acted quickly enough to make that kind of cash, or whether the person is guilty of insider trading to begin with. Both CNBC and The Wall Street Journal emphasize that Reuters is not a target of this investigation.

After the denials from both companies, Reuters adjusted its story to note that talks had been held between "advisors" rather than executives from Samsung and BlackBerry. No one has been formally accused of wrongdoing, and with insider trading cases often daunting to prove in court, it could stay that way.