A month that started out with a bang went out with a whimper -- only the greediest of bulls will complain, however.

The major stock-market indices did virtually nothing on the last day of 2010, but December’s performance was nevertheless an impressive one. Indeed, for the S&P 500, this month’s gain represented about half that of the full year.

The Dow Jones Industrial Average added 7.80 to 11577.51, the Nasdaq Composite eased 10.11 to 2652.87, and the S&P 500 eased by 0.23 to 1257.65.

Not surprisingly, New Year’s Eve volume was paltry, and there was little in the way of corporate news or economic data. The Institute for Supply Management-New York said its current business conditions index rose to 70 this month, from 65.6 in November. The group’s six-month outlook index jumped to 75.2 from 71.9.

The question on the minds of investors now is what awaits the economy and the markets next year. Recent data points have been generally favorable, but still choppy, and there is surely no indication that the economy is out of the woods. In fact, there may be parts of the economy that are actually deteriorating again, particularly in the housing arena.

But those worries will wait until Monday. For now, investors can enjoy this year’s gains: the Dow rose by 10.9%, the Nasdaq Composite by 17.4% and the S&P 500 by 12.8%.

In corporate news, Clearwire Corp. (CLWR) chairman Craig McCaw will resign immediately, the company said late yesterday.

Dow Chemical (DOW) is being sued by K+S AG, which says it overpaid for Dow's Morton Salt unit.

CVS Caremark (CVS) said it will buy the Medicare Part D business of Universal American, a Medicare Prescription Drug Plan sponsor, for $1.25 billion.

According to the UK newspaper the Daily Mail, Sony Corp. (SNE) is mulling a $40-a-share bid for Imax Corp. (IMAX). The newspaper also said Walt Disney Co. (DIS) may be considering an offer for the company.