The reporting period heats up this week, and with the S&P 500 already up 14 percent so far this year, investors are hoping results and guidance will justify the relatively high valuation of stocks.
It came a day after the index broke through the 23,000 level for the first time, although it fell back to close below the milestone.
The S&P and the Nasdaq also notched opening records on gains across the board.
"The good news is the number of companies now beating estimates, and the margin by which they are doing so, is running above what these same 52 companies have recorded, on average, over the past three years and their top-line revenue growth has accelerated more", said Nick Raich, CEO of The Earnings Scout, in a note. "All the news is positive".
Benchmark U.S. crude gained a penny to settle at $51.88 a barrel on the New York Mercantile Exchange.
Seven of the 11 major S&P sectors were higher, led by a 0.31 percent gain in the financial index.
At 9:38 a.m. ET (1338 GMT), the Dow Jones Industrial Average was up 116.49 points, or 0.51 percent, at 23,113.93, the S&P 500 was up 3.7 points, or 0.14 percent, at 2,563.06 and the Nasdaq Composite was up 6.91 points, or 0.10 percent, at 6,630.57. JPMorgan was up 2.1 percent, while Bank of America was up 1.6 percent. S&P 500 companies are forecast to deliver 3.3 percent earnings growth in the third quarter, according to S&P Global Market Intelligence.
Winners and Losers: Freeport-McMoRan sunk 2.23 percent after Deutsche Bank downgraded the mining company's stock to "Sell". Shares of the American health care company soared 5.58 percent.
Advancing issues outnumbered decliners on the NYSE by 1,669 to 815.