The S&P 500 posted a slight gain on Thursday, led by strong quarterly results from Microsoft, as Wall Street slogged through the busiest day of the earnings season.
The broad index climbed 0.2% to 3,010.29. The Nasdaq Composite gained 0.8% to close at 8,185.80.
Microsoft reported earnings per share of $1.38 on revenue of $33.06 billion for the previous quarter. Analysts polled by Refinitiv expected a profit of $1.25 per share on revenue of $32.23 billion. Microsoft's strong quarterly performance was driven in part by Azure, its cloud business, which saw revenues grow by 59% on a year-over-year basis. The stock closed 2% higher.
"MSFT delivered strength across the board with no blemishes and importantly gave stronger than expected December quarter guidance which speaks to an inflection point in deal flow as more enterprises pick Redmond for the cloud," Dan Ives, an analyst at Wedbush Securities, said in a note.
The Dow Jones Industrial Average struggled, however. The 30-stock index fell 28.42 points, or 0.1% to 26,805.53 as shares of 3M pulled back 4.1%. 3M cut its full-year earnings forecast, overshadowing stronger-than-expected results for the quarter.
Overall, the major indexes struggled for direction as investors tried to make sense of the corporate earnings.
"For the market to really cheer this, we're going to have to see more companies beat estimates and raise guidance," said Rob Haworth, senior investment strategy director at U.S. Bank Wealth Management.
Forty-five S&P 500 companies were on deck to report earnings on Thursday. Some of the companies posting their results before the bell include 3M, NBCUniversal-parent Comcast, Dow Inc. and Twitter. Amazon, Intel and Visa are among the companies scheduled to report after the bell.
Comcast shares dipped nearly 2% after reporting while Dow Inc climbed 4.7%. Twitter, however, fell 20.8% on weaker-than-expected results.
Tesla shares spiked more than 17% after the electric car maker posted a surprise quarterly profit. The company also told investors its new Shanghai factor is "ready for production." PayPal, meanwhile, jumped 8% after posting its best results in at least a year.
More than 31% of S&P 500 companies reported quarterly earnings through Wednesday morning, with nearly 80% of them posting results that beat analyst estimates, according to FactSet.
"Thus far earnings have been generally supportive of further progress and a number of potential minefields in the industrial sector have been navigated successfully," Michael Shaoul, chairman and CEO of Marketfield Asset Management, wrote in a note.
In economic news, durable goods orders fell 1.1% in September, notching their largest drop in four months. The drop in orders comes as the world struggles with a global manufacturing slowdown. The Institute for Supply Management said earlier this month that manufacturing activity in the U.S. fell to its lowest level in a decade.
—CNBC's Silvia Amaro contributed to this report.