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 bank card processing specialist Heartland Payment Systems (NYSE: HPY) jumped as high as 14.5% overnight on heavy volume after reporting second-quarter results.

So what: The longtime Motley Fool Hidden Gems recommendation missed Wall Street's revenue targets but blasted past earnings expectations, and then raised full-year earnings guidance past Street estimates. Heartland broke a long streak of missed estimates in the first quarter and now has the beginnings of a much more appetizing sequence in play.

Now what: That is if the small-cap with the big CAPS rating doesn't get gobbled up by one of its larger and richer competitors. Heartland is a minnow next to industry peers Global Payments (NYSE: GPN), Western Union (NYSE: WU), or Equifax (NYSE: EFX), and if neither these companies nor card servicers Visa (NYSE: V) or MasterCard (NYSE: MA) show an interest in Heartland's predictable cash flow growth, then private equity firms could step up to the plate. That's exactly what happened to larger rival First Data four years ago, after all.

Interested in more info on Heartland Payment Systems? Add it to your watchlist.