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: Green Dot (Nasdaq: GDOT) popped 12% in intraday trading today, after competitor Western Union (NYSE: WU) reported better-than-expected earnings and raised guidance.

So what: Western Union's EPS of $0.42 beat the $0.38 consensus estimate and rose 19% year over year. Its revenue of $1.37 billion beat the $1.33 billion consensus forecast and rose 7% year over year. Management raised 2011 EPS guidance to between $1.48 and $1.53, from previous guidance of $1.41 to $1.46.

Now what: In May, Green Dot missed earnings expectations but boosted its full-year outlook. Its volatile stock has fallen by more than half from its 52-week high this year in a series of plunges. Revenue growth of more than 35% in Western Union's electronic channels business, which accounts for 3% of revenue and competes with Green Dot, bodes well for Green Dot's outlook, as does Western Union's improving confidence in its outlook.

Interested in more info on GDOT? Add it to your watchlist by clicking here.

Fool contributor Cindy Johnson does not own shares of any company named above. 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.