The presidential emoluments clause is in the Constitution [0], but as recent events show, the Constitution is being bent, folded, spindled and shredded by cronies in black nightgowns.
From [0]
> The emoluments clause, also called the foreign emoluments clause, is a provision of the U.S. Constitution (Article I, Section 9, Paragraph 8) that generally prohibits federal officeholders from receiving any gift, payment, or other object or service of value from a foreign state or its rulers, officers, or representatives. The clause provides that:
> No Title of Nobility shall be granted by the United States: And no Person holding any Office of Profit or Trust under them, shall, without the Consent of the Congress, accept of any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince, or foreign State.
> The Constitution also contains a “domestic emoluments clause” (Article II, Section 1, Paragraph 7), which prohibits the president from receiving any “Emolument” from the federal government or the states beyond “a Compensation” for his “Services” as chief executive.
Insider trading is legislated separately, if legislation still matters.
[0] https://www.britannica.com/story/what-is-the-emoluments-clau...
"Former Pakistani Prime Minister Benazir Bhutto and her husband, Asif Ali Zardari, were long accused of stealing more than $1.5 billion from Pakistan through various state contracts, kickbacks, and offshore bank accounts"