The Nasdaq composite eked out a record close on Wednesday, led by gains in Amazon.
The tech-heavy index closed 0.1 percent higher at 6,867.36 as Amazon gained more than 1 percent. Amazon shares rose after CNBC reported the company's cloud business is about to announce a huge health-care deal with Cerner, one of the largest health technology companies in the world.
The Nasdaq has now posted record closes in back-to-back sessions; it also hit an intraday high on Wednesday.
The S&P 500 and Dow Jones industrial average, meanwhile, finished lower after Federal Reserve expresses concern about the impact of the market's sharp rise on the economy in a summary of its previous meeting.
The Dow declined 64.65 points to close at 23,526.18, with DowDuPont declining 0.9 percent to lead decliners.
The fell 0.1 percent to 2,597.08, with financials and real estate as the worst-performing sectors. HP Enterprise was the worst-performing stock in the index.
The minutes from the Fed's Oct. 31-Nov. 1 meeting showed the central bank's officials have started to worry that market prices are getting out of hand and are posing a danger to the economy.
"I think the Fed is torn here," said Kathy Jones, chief fixed income strategist at Charles Schwab. "They want to raise interest rates and they are concerned that if asset prices keep going higher, they could get bubbly and burst. But at the same time, they can't get inflation to go up."
Some members feared what would happen if the market suddenly took a hit.
"In light of elevated asset valuations and low financial market volatility, several participants expressed concerns about a potential buildup of financial imbalances," the minutes stated.
Equities have been on fire this year, with the S&P 500 rising more than 15 percent and volatility remaining subdued.
Losses on the Dow and S&P 500 were muted by strong corporate earnings. Tractor maker Deere reported quarterly earnings and revenue that surpassed analyst expectations. The company's stock jumped 4.3 percent. Deere also issued strong earnings guidance for the coming fiscal year.
HP Enterprise on Tuesday also reported better-than-expected sales and earnings, but its stock fell more than 7 percent after CEO Meg Whitman announced she will step down from her role early next year.
Salesforce and Gamestop's earnings also topped analyst expectations.
Overall, this earnings season has been solid. With 97.8 percent of the S&P 500 having reported, calendar third-quarter earnings are up 6.25 percent on a year-over-year basis, according to FactSet. Also, about 74 percent of companies have posted earnings that have surpassed expectations.
The three major indexes closed at record highs on Tuesday, led by a sharp rally in tech stocks.
"New highs were the undeniable theme once again on Tuesday," said Frank Cappelleri, executive director at Instinet, in a note to clients. "It happened for the S&P 500 and for many, many other indices, ETFs and stocks. Broad participation and a proliferation of uptrends have helped this remain the case all year."
On the data front, durable goods orders fell 1.2 percent in October; economists polled by Reuters expected a 0.3 percent increase. Meanwhile, weekly jobless claims hit 239,000, just below an estimate of 240,000.
—CNBC's Jeff Cox contributed to this report.