A video board projects the day's numbers after the closing bell of the Dow Jones at the New York Stock Exchange on March 31, 2017.Bryan R. Smith / AFP / Getty Images

On its face, the tweet was one of the most innocuous President Trump has ever sent—a plain-vanilla reminder early Friday morning that the monthly federal jobs report was coming out in an hour’s time.

“Looking forward to seeing the employment numbers at 8:30 this morning,” the president wrote at 7:21 a.m. ET.

No exclamation points. No all-caps. No gratuitous insults, partisan jabs, or demands that his opponents be investigated.

For Trump, this was boring, even low-energy. Except this nothing-burger of a tweet may have moved billions, if not trillions, of dollars on the global market and sent the community of economists and investors who scrutinize the jobs report into a tizzy.

At precisely 8:30 a.m. ET on the first Friday of every month, the Labor Department’s Bureau of Labor Statistics releases a summary of employment in the United States. The data is culled from two separate reports that show, among other things, how many jobs the private and public sectors gained or lost in the previous month and whether wages went up or down. The headline figure is almost always the national unemployment rate, which in May fell to an 18-year-low of 3.8 percent.

To say the jobs report is closely held is an understatement. It is treated as a state secret until the moment the data is released to the public, so that no stock trader—whether in the U.S. or abroad—can get even the slightest advantage over anyone else. Reporters who cover the monthly jobs report are shepherded into a locked room at the Labor Department and instructed to leave their cellphones outside until the clock strikes 8:30 a.m., at which point market-watchers see a flurry of tweets and emails with the key figures.

Of course, the president gets a peek in advance, through a briefing the day before. But they traditionally say nothing until the data becomes public; there’s even a federal rule barring employees of the executive branch from commenting on leading economic indicators, including the monthly jobs report, until an hour after they are released. Trump has broken this rule before, tweeting about a positive jobs report at 8:45 a.m. ET last August.

The White House on Friday defended the president’s tweet as appropriate because he didn’t reveal the numbers. Trump economic adviser Larry Kudlow said on CNBC Friday morning that he personally told the president about the jobs report Thursday on Air Force One. “He chose to tweet,” Kudlow said. “I don’t think he gave anything away incidentally,” he added.

But that was beside the point. Any indication from the president that the report was positive is all someone would need to know to make a decision on a trade. And the simple fact that Trump tweeted about it at all was indication enough.

The Dow Jones Industrial Average and the broader S&P 500 each jumped higher at Friday’s open on the strong report, which in addition to the lower unemployment rate showed that the economy added 223,000 jobs and wages grew in May. The Wall Street Journal reported Friday that the yield on the benchmark 10-year Treasury note rose after Trump’s tweet, as did the WSJ Dollar Index.

To Trump’s critics, the bigger fear wasn’t so much his Friday tweet to the public as was the possibility that the famously chatty president privately bragged about the report to his wealthy friends or family members on Thursday night. “There is a big question about who he privately leaks data to and that should be investigated,” tweeted Betsey Stevenson, formerly the chief economist at the Labor Department during the Obama administration.

The topic is especially sensitive for ex-Obama officials. During the run-up to the 2012 election, the monthly indications of the nation’s recovery from the Great Recession were invested with as much political significance as public polling, to the point where former General Electric chairman Jack Welch baselessly accused the “Chicago guys” of juking the numbers weeks before the election.

“If during the Clinton or Obama Administrations there had been a statement from @POTUS or anyone senior official in the morning before the Employment Report it would have been a major scandal—with all sorts of investigations following on,” Larry Summers, the Clinton-era treasury secretary who served as chairman of Obama’s National Economic Council, tweeted on Friday morning.

The outrage at Trump’s tweet was, perhaps predictably, one-sided. Republicans focused on the bigger picture—one more indicator of a healthy economy that they hope will be their electoral salvation this fall. Democrats were left to cringe at another fallen norm, tossed to the wayside by the blandest of presidential tweets.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.