President Trump’s relatives return to Washington with more political and cultural support — and a far better understanding of how to wield their soft power.

The president-elect and his family have a direct and potentially lucrative stake in the sale of a cryptocurrency product that surged in value in the hours after going on sale, days before his inauguration.

President-elect Donald J. Trump has a range of new business ventures that could expose him to even greater potential conflicts of interest than during his first term.

The president-elect is set to arrive in the Washington area on Saturday and begin a series of events that includes a party at Trump National Golf Club and a rally at Capital One Arena.

The measures, which were immediately called insufficient by ethics lawyers, included appointing an outside lawyer and limiting Mr. Trump’s access to detailed financial information.

Hussain Sajwani, the founder and chairman of DAMAC Properties of Dubai, built the first Trump-branded golf course in the Middle East a decade ago.