The numbers: The number of job openings in the U.S. climbed to a record 6.94 million in July in a clear sign that a booming economy is entering the second half of the year with a big dollop of momentum.

Job openings rose from 6.82 million in June, the government said Tuesday.

About 5.68 million people were hired and 5.53 million lost their jobs in July. Such a high level of what economists call “churn” is common in the huge U.S. economy.

The share of people who left jobs on their own, known as the quits rate, rose a notch to a 2.7% among private-sector employees. The record is 2.9%, set in 2001.

The quits rate was 2.4% among all workers — also near a record high. The government began keeping track in 2000.

Workers who switch jobs usually get better pay than those who remain in their old ones. And more people switch when they are confident about the economy.

Read:Bigger pay raises are coming for millions of Americans thanks to sinking unemployment

What happened: Job openings increased the most in insurance, finance and manufacturing.

Retailers slashed help-wanted ads by 85,000, reflecting ongoing struggles among old-line brands as shopping shifts heavily toward the internet.

Job openings for education and government also declined.

Big picture: The U.S. economy is booming. Growth surged in the spring and has carried through summer. Unemployment is uber-low at 3.9%, layoffs are at a 50-year low and small-business owners say they are more optimistic about the economy than ever.

Some workers are taking advantage of the strong economy and tight labor market by switching jobs in search of better pay. As a result, companies are offering more attractive pay and benefits to lure new workers or to retain old ones.

Read:U.S. adds 201,000 jobs as worker wages accelerate to nine-year high

Also Read:Jobless claims fall to 203,000. They haven’t been this low since Dec. 6, 1969

Market reaction: The Dow Jones Industrial Average DJIA, -1.92% and the S&P 500 SPX, -2.37% rose on Tuesday to finish higher after a wobbly start. The Nasdaq COMP, -3.01% rose. The stock market has moved lower in September after a big rally in August.