– Wall Street is enjoying its third record-setting run of this year, with the major stock indexes delivering a string of all-time highs in recent weeks.

The S&P 500 has set new highs 23 times this year through Monday, up from 19 last year. The benchmark index, which closed above 3,100 points for the first time last week, also broke records in April and July.

The Dow Jones industrial average, which climbed above the 28,000 mark for the first time last week, has set 12 records so far this year, trailing the 15 it set last year. Meanwhile the technology heavy Nasdaq composite has marked 23 new highs as of Tuesday, beating last year’s 16 times.

The S&P 500 and Nasdaq are now up by more than 20% this year, while the Dow is up nearly 19%.

The indexes’ latest record-setting run has extended the life of the longest-ever bull market for stocks, which marked 10 years in March after nearly falling 20% in December.

“If you look back over history, new highs tend to clump together in secular bull markets,” said Willie Delwiche, investment strategist at Baird. A secular bull market typically runs several years, weathering cycles of heavy selling.

“That’s what we’ve been in the past few years and there’s not evidence at this point that’s ended,” he added.

The market began grinding out new highs in late October after emerging from a late-summer slump caused by fears that the U.S. economy could be headed for a recession.

Those concerns have eased as investors have been encouraged by surprisingly good third-quarter corporate earnings, a third interest-rate cut by the Federal Reserve and other data showing the economy hasn’t slowed as much as economists feared. Hopes that the U.S. and China can make progress on a trade deal have also helped keep investors in a buying mood.

Still, the gains have been concentrated among the market’s biggest companies. Apple, Microsoft, Google’s parent Alphabet, Walt Disney, AT&T and JPMorgan Chase all hit all-time highs this month. And all have outgained the overall S&P 500 so far this year, except for Alphabet, which has matched the index’s gain of about 24%.

“You’d like to see a lot of individual stocks making new highs along with the indexes and that’s not happening right now,” Delwiche said. “A handful of stocks are driving the indexes higher.”

Technology stocks have led the way as the market racked up milestones this month. As of Tuesday, the sector was up more than 41% so far this year, well ahead of the other 10 sectors in the S&P 500.

Communication services, industrials and financials are also holding on to solid gains. Energy is trailing well behind the rest of the pack.