Traders react after the closing bell on the floor of the New York Stock Exchange (NYSE).

Companies are on pace to post the most earnings beats in at least a decade, according to John Butters, senior earnings analyst at FactSet.

Butters said in a note that 80 percent of the companies that have reported quarterly results through Friday have posted better-than-expected earnings. "If 80% is the final number, it will mark the highest percentage since FactSet began tracking this metric in Q3 2008," he said in the note Friday.

Much of the earnings outperformance comes from telecom, health-care and tech companies, Butters noted. All of the S&P 500 telecom companies have reported better-than-expected earnings this season, while 96 percent of health-care companies have outperformed earnings expectations. In tech, 93 percent of company earnings have exceeded forecasts.

Through Friday, 81 percent of S&P 500 companies had released their latest quarterly reports. Some of the companies that have reported better-than-expected results include major banks J.P. Morgan Chase and Bank of America as well as tech giants like Amazon and Apple.