The Dow Jones Industrial Average broke through 20,000 points for the first time at the start of trading Wednesday morning, reaching a new milestone and continuing an extraordinary run that began on the morning after Donald Trump won the presidential election.

The Dow is the most familiar index of the performance of shares traded on Wall Street, and measures the performance of 30 companies, most of which are traded on the New York Stock Exchange. Several are also traded on the NASDAQ exchange.

During the last recession, the Dow fell from a high of 14,164.43 on October 9, 2007 to a low of 6,547.05 on March 9, 2009. It had continued to fall for the first several weeks of President Barack Obama’s first term — particularly, it seemed, after major policy speeches — but stabilized after most of the country’s major financial institutions passed a stress test in the spring of that year. Since then, the Dow has climbed throughout the Obama era, breaking new records regularly in a long “bull market.”

The markets had expected Democratic presidential nominee Hillary Clinton to win the 2016 election. Stocks fell for several days straight after FBI Director James Comey announced a re-opening of his agency’s probe into Clinton’s email server on Oct. 28. The markets rallied again on Nov. 7, the day before the election, after Comey announced that his investigation had concluded there were no new grounds to prosecute Clinton.

On Election Night, as Republican nominee Donald Trump began to look suddenly like the winner, Dow futures dropped sharply, by 900 points. But soon after markets opened the next day, the markets began to rally, and have not looked back. Led by Goldman Sachs — which has several alumni in prominent positions in the incoming administration — the Dow rose nearly 1,700 points from November 9 until December 20. It hovered near 20,000 for weeks before finally breaking through the 20K mark.

History will note the gains on President Obama’s watch, but analysts are already calling the post-election rally the “Donald Trump bounce” or the “Trump bump.” As of January 25, 2017, Dow 20K is undoubtedly a Trump administration milestone.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He was named one of the “most influential” people in news media in 2016. His new book, How Trump Won: The Inside Story of a Revolution, is available from Regnery. Follow him on Twitter at @joelpollak.