A single post from Donald Trump on Truth Social caused the stock value of his media company, Trump Media and Technology Group, to soar, increasing his net worth by about $500 million, CNN reported.

Previously, shares of Trump Media were down after initially rising following his election victory earlier in the week. As the market opened Friday, the stock was down 42% from its high since Wednesday.

In the stock market, it is common for traders to buy shares before a favorable event for a company, only to then sell them to secure their profits. This pattern was playing out in Trump’s media until Trump intervened.

On Friday, as stocks fell again, Trump posted a message on Truth Social, saying he had no plans to sell his stock in the company. “There are false, untrue and possibly illegal rumors and/or statements, perhaps made by market manipulators or short sellers, that I am interested in selling shares of Truth,” said Trump.

Following his inauguration, the stock rebounded, climbing nearly 15% at the end of the day. As the company’s largest shareholder, Trump owns approximately 114.75 million shares, the value of which increased from $3.2 billion to $3.7 billion after the takeover. However, for the week, Trump Media’s stock only gained about 4.4%.

As the election approached, with Trump and Vice President Harris running very close in most polls, betting markets leaned toward Trump, prompting investors to invest heavily in assets that they would be influenced by his leadership.

That optimism fueled a roughly 200% rise in Trump Media shares in the six weeks before the election. Trump previously said in September that he would not sell his shares or leave the platform he created.

With nearly 115 million shares, Trump owns about 53% of Trump Media, bringing his stake to about $3.7 billion as of Friday’s stock price, when the company’s total market capitalization was close to $7 billion.

(With contribution from agencies)