As President Donald Trump stood on a podium in Pennsylvania's Lehigh Valley, he went apparently off script to name check a pair of companies (1). Pharmaceutical giant Eli Lilly, which he called "a great company," was touted for investing $3.5 billion in a manufacturing facility. And Nokia, he said, was investing $30 million to expand its semiconductor packaging and testing facility.

The companies got the shout-outs for bringing jobs to the state and for their investments in American facilities. But when Trump talks positively about publicly traded companies, skeptics start probing deeper.

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Since the beginning of his second term, Trump has mentioned many companies that Americans later learned he had invested in personally. Often the disclosure of those stock purchases doesn't come about until well after the favorable mention. (He has not disclosed any ownership stake in Nokia, but holds shares (2) in Eli Lilly.)

Trump's assets are in a trust managed by his children. However, unlike for past presidents, it's not a blind trust. He knows what is in it. According to reporting by PBS, having a leader who appears to profit so directly from the office is "an unprecedented practice for a sitting U.S. president in the modern era," even though there is no specific law against it (3).

A favorable mention by the executive branch can be a big boost for a company. Here's a look at what has happened with other businesses Trump has talked up in speeches and interviews.

Micron

On March 26 of this year, Trump went on Fox News' "The Five" and said he had recently met with executives at Minnesota-based semiconductor company Micron (4). "I just left the head of Micron. It's one of the hottest companies," Trump said. What he left out was he had purchased (5) between $50,000 and $100,000 in the company's stock the day before — and had bought shares three times prior to that, bringing his total investments to between $217,000 and $530,000 (6).

Shares of Micron since that date have gone up more than 230%. Much of those increases, however, are due to analyst upgrades and the AI rally. Shares were up more than 12% Thursday following a gangbusters earnings beat after the market closed Wednesday.