The Dow Jones industrial average temporarily broke through the 22,000-barrier for the first time this morning, on the heels of a better-than-expected sales forecast from Apple.
The milestone comes in a year of strong corporate profits, which have driven the Dow up 11 percent this year.
Technology stocks have performed especially well, with the Standard & Poor's 500 technology sector index up 23 percent.
Stock prices have been rising for years and took an especially strong jump after the election of Donald Trump. The Dow is up more than 20 percent since November.
Prices fell back a bit in the spring, a drop that many analysts attributed to waning optimism about tax reform and deregulation.
But since then, strong corporate profits have helped propel the market higher. The falling dollar has helped sales for companies such as Boeing and Apple that sell a lot overseas.
After the close of the market on Tuesday, Apple released an unexpectedly strong sales forecast, which sent its shares soaring to a record this morning.
"The tech sector as a whole has some room to appreciate," Brad McMillan, chief investment officer for Commonwealth Financial Network, told The Wall Street Journal. But he said investor appetite is being driven by a few sector giants.
"When you look at the history of stocks that could do no wrong, usually it ends up in tears," he said.
The Dow, which consists of 30 blue-chip stocks, is the best known stock index in the world, although most stock analysts caution that it is an imperfect measure of economic health.