The Dow was perfectly unchanged on Tuesday, a rare occasion on Wall Street

You wouldn’t have known the stock market was open on Tuesday just by looking at the Dow Jones Industrial Average.

The 30-stock average closed flat going out to at least six decimal places. It’s rare for trading to be this futile. The last time the Dow closed perfectly unchanged was April 24, 2014. It’s the third time the Dow has closed perfectly unchanged since 2000.

The unchanged close came despite some action during the trading day. The Dow flirted with a record high, rising as much as 79.37 points to trade about 4 points below its all-time high of 27,774.67. President Donald Trump gave a big economic speech in New York but traders by the end of the day determined they had heard most of what he said on trade and the Federal Reserve before.

Closes like the Dow’s on Tuesday are also unusual for other indexes. The S&P 500 has closed unchanged through two decimal places just 10 times since 1980. The last time it ended a session so flat was Jan. 10, 2017.

—With reporting by CNBC’s Robert Hum, Gina Francolla and Chris Hayes.

Subscribe to CNBC on YouTube.