Investors have learned one key thing during this record-setting stock market advance: Ignore Trump's tweets

  • Investigations of Russia interference in the election, North Korea, members of his own administration, federal judges — none of it was off limits in President Trump's Twitter feed.
  • The S&P 500 rose more than 19 percent last year and hit 64 record-high closes, despite the tweets.
  • Stock markets react strongly to some words, but not so much to Trump's Twitter account.
Trump Twitter
Jaap Arriens | NurPhoto | Getty Images

Some words have enormous influence on the stock market. And then there are social media posts by President Donald Trump.

During his first year in office, Trump didn't disappoint his followers on Twitter, rattling off a nearly daily diary of personal thoughts and reactions to news events, real or imagined slights, and popular culture. Some of his most memorable tweets of the last year coincided with big political developments — or were the reason behind them. Yet they barely seemed to move the stock market.

Investors certainly benefited. While the S&P 500 rose more than 19 percent last year, the index barely budged on the days of some of Trump's most incendiary comments. And it managed to notch 64 record-high closes. That streak has continued this year. Here's a look back.

Nevermind that Russia stuff

Five days after inauguration, on what turns out to be the day after his National Security Advisor, Mike Flynn, was interviewed by the FBI about conversations with the Russian ambassador (Flynn later pleaded guilty to lying to the FBI in that interview), Trump took to Twitter to complain about voter fraud. He seemed to be under the impression that millions of illegal votes cost him the popular vote. His allegations have never been proven.

The S&P rose that day 0.8 percent, closing at its third record high of the year.

Remember the travel ban?

A little more than a week after Trump issued his Muslim travel ban, a federal court in California blocked it, prompting this criticism.

That was a Sunday. The next day the S&P closed down 0.2 percent. Later that week, the S&P would begin a five-day record streak.

Then there was the whole wiretapping thing

By now the House Intelligence Committee had opened its investigation into Russian interference with the election and word was out that Jeff Sessions, the Attorney General, had met with the Russian ambassador in 2016. Sessions recused himself from Russian investigation matters on March 2. Two days later came this tweet:

That was also on a weekend. That Monday, the S&P fell 0.33 percent.

Ok some stocks did react, temporarily

One tweet did sent drug company shares tumbling, when Trump said he was working on a new system where there would be competition in the industry. Mylan fell 1.6 percent that day and Allergan fell 1.14 percent. Both stocks would recover, and while Allergan closed down for the year, shares of Mylan rose 8 percent.

The S&P fell 0.3 percent that day.

The reverse was also true, as in the case of Nordstroms. In early February the retailer announced plans to drop Ivanka Trump's clothing line after poor sales. The stock jumped 5 percent the day this came across her dad's feed:

Nordstrom shares ended the year flat. The S&P 500, meanwhile, traded up just 0.07 percent the day the tweet appeared.

Maybe there are tapes!

The Russian investigations heated up all spring. On May 9, Trump fired James Comey, the FBI director. Three days later came this tweet:

The S&P fell 0.16 percent that day.

It's a witch hunt

Robert Mueller was named special prosecutor for the Russia investigations on May 17, and the next day, this appeared:

The S&P climbed 0.37 percent.

Locked and loaded

North Korea engaged in some provocative activity last year, including firing a ballistic missile capable of reaching Alaska. Trump's rhetoric escalated. In August he said he would rain down "fire and fury like the world has never seen" if North Korea continued to threaten the U.S. Then came this tweet:

The S&P rose 0.13 percent that day.

Trolling the 'rocket man'

Trump continued to lash out against North Korea into the fall months, adding a new nickname for the country's leader in a series of tweets including this one:

That was a Saturday. The next Monday the S&P fell 0.22 percent.

Trump also used mocking tones to troll the North Korean leader, as in this tweet:

That was also a weekend. The next Monday, the S&P rose 0.1 percent.

Tweets that raise more questions

Then there were the tweets that got people reading between the lines. Was the president saying he knew more than he claimed? That's the question provoked by this message:

This was again over a weekend. That Monday the stock fell 0.11 percent. The S&P would go on to set five more record high closes for the year.

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