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 industrial-pumps purveyor Colfax (NYSE: CFX) slumped as much as 13% today as investors voted with their feet against a planned merger in the making.

So what: On Monday, Colfax bid $2.4 billion to acquire competitor Charter International PLC. Yet at that price, Colfax says it won't earn a return on its investment for at least three years and may need as many as five years for the deal to become accretive.

Now what: Colfax's bid works out to 914 British pence per share of Charter, trumping a lower 850 pence bid from turnaround specialist Melrose -- a lower bid that Charter has twice already rejected. There's no guarantee that Charter shareholders will be more receptive to Colfax's bid -- indeed, Charter shares rose only as high as 858 pence on the offer. But already Colfax investors seem to be looking at this like a done deal and punishing Colfax for overpaying. When you consider that Colfax shares already cost 30 times earnings, that earnings growth was supposed to average 15% per year before the buyout, and that by its own admission, Colfax says buying Charter will hurt earnings for years to come ... I can't blame investors for bailing.

Will investors regret abandoning Colfax in its moment of "triumph"? Add it to your Watchlist and find out.