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 money-transfer giant Western Union (WU -2.21%) plummeted 28% today, after its quarterly revenue and full-year guidance missed Wall Street expectations.

So what: Western Union's third-quarter profit managed to squeak past estimates, but a top-line miss -- $1.42 billion versus the consensus of $1.47 -- coupled with downbeat guidance for the full year is triggering serious concerns over decreasing market share. In fact, management even announced price reductions in key corridors to help fight off the competitive pressures and, in the process, squashed any hopes that Wall Street had of a near-term earnings recovery.

Now what: Western Union now sees full-year adjusted EPS of $1.65-$1.68, down significantly from its prior view of $1.73-$1.77. According to CEO Hikmet Ersek:

We are a leader in a growing market in consumer money transfer, and we are taking steps to enhance our position for the future. We will continue to execute our strategies in business-to-business, digital, and stored value.

With management seemingly backing up that optimism by raising its dividend 25%, and upping its repurchase plan, today's plunge might be a solid bargain opportunity for long-term income investors.