Gloomy beginnings bring us this week’s Marketplace Money buzzword: Merger Monday.

Merger Monday was the nickname Wall Streeters gave to the first day of the week, ’cause it’s the day many companies chose to announce their latest acquisitions. Those announcements set the tone for the week’s trading, sometimes leading to big gains.

But now, the biggest Monday merger will probably be between worry and fear. After last week’s stock market plunge, the banks who facilitate mergers have got cold feet.

So for a while, anyway, bankers will be singing “Rainy days and Mondays always get me down . . .”