Earnings for the quarter are now expected to have risen 0.7% from the year-ago quarter, based on results from 193 S&P 500 companies and estimates for the rest.

At the start of the month, analysts had been expecting a 0.3% year-over-year decline in fourth-quarter earnings, per Refinitiv's data.

Investors have been keeping a close eye on fourth-quarter results following a slight fall in third-quarter earnings, the first year-over-year decline for the S&P 500 since 2016.

Stronger-than-expected results recently from top technology names Microsoft, Apple and Intel contributed the most to the improvement so far in the fourth-quarter forecast, while Boeing Co's results were a drag, said David Aurelio, senior manager of equity markets research at Refinitiv.

With the fourth-quarter results, major U.S. corporations are closing the books on a lackluster year of profit growth. But bullish investors have been hoping companies can shore up confidence that 2020 will show significant profit improvement in order to keep the stock market's rally going.

By Caroline Valetkevitch