At 70 years old, no one can tweet like Trump. Without Twitter, it is questionable whether he would even be president. With a single tweet, he has literally changed stock prices, influenced currency exchange rates, and even changed the policy positions of foreign leaders.

For the first time in history, the President of the United States will continue to use Twitter to announce policy, contact foreign leaders, negotiate with businesses, and combat what he views as “fake news” and unbalanced media coverage.

We’ve all heard the phrase, “power of the pen.” Below we’ll explore four examples of the “value of a tweet.”

#1: The President-elect Thinks His New Plane is Going to Cost Too Much

Impact = - $1.5 billion

On December 22, before being sworn in as president, Donald Trump was already trying to reduce defense spending by suggesting a bidding war between current vendor Lockheed Martin and Boeing to produce the new defense aircrafts:

https://twitter.com/realDonaldTrump/status/812061677160202240

This public announcement took a big hit on the aerospace, defense, and security company. Lockheed Martin’s stock closed at 252.81 on December 22, and the next day, it opened at 248.07, losing almost 2% of its value.

At today’s market capitalization of $75.1 billion, a 2% drop equals about $1.5 billion in lost value -- that’s an expensive tweet.

#2: Get Back Here and Make Henry Ford Proud

Impact: + 1.5 Billion

On January 4, Trump broke the news on Twitter that Ford had decided to cancel the construction of a new plant in Mexico to create 700 new jobs in the U.S.:

https://twitter.com/realDonaldTrump/status/816635078067490816

Trump’s positive message for the automotive enterprise caused their stock to raise its value from 12.14 to 12.54 (+3.2%) in just a few hours.

A $3.2% rise at Ford’s current price is worth about $1.53 billion -- thats a lot of zeros.

#3: That’s Going to Be a Pricey Trip to Baja, Toyota

Impact: -$4.5 billion

The next day, Trump strongly criticized Toyota Motors for deciding to build their new plant in Mexico rather than in the U.S. and threatened the Japanese company with a big border tax:

https://twitter.com/realDonaldTrump/status/817071792711942145

The company’s stock value in the U.S. market was at $121.35 and dropped to $119.72 after the tweet. One week later, the value dropped even lower to $118.47, losing a total of 2.37%.

The cost of that tweet? Around $4.5 billion!

This phenomenon is not limited to stock and options markets.

#4 - Hey, Necesitamos Un Muro. Págalo!

Impact: -16% of MXN value

On January 26, President Trump tweeted about the possibility of canceling a meeting with Mexico’s President Enrique Peña Nieto if they kept refusing to pay for the southern border wall:

https://twitter.com/realDonaldTrump/status/824616644370714627

Before the tweet, the peso’s value compared to the U.S. dollar was $20.9, but only an hour after Trump’s rant on social media, the peso lost 1% of its value, going to $21.2 (meaning a U.S. dollar could purchase more pesos). In general, the Mexican peso has lost around 16.4% of its value since Donald Trump won the election on November 8.

Traditionally, we’d see these types of stock market and currency movements when a Federal Reserve chairperson would give an hour long, often very cryptic testimony to Congress.

Donald Trump seems to be able to move the market 140 characters at a time.

What remains to be seen is if these movements will have lasting impact or if their effect will lessen as markets become conditioned to the president’s favorite pulpit.

Editor’s note: This article was a collaboration between authors Debbie Benrey and Rafael Benrey.