Billionaire businessman Howard Lutnick will face a senate hearing on Wednesday for his nomination to be Donald Trump’s secretary of commerce, as questions swirl over whether his pledge to unwind his significant holdings will be enough to avoid numerous conflicts of interest.

WASHINGTON—Howard Lutnick’s journey from Wall Street veteran to one of President Trump’s most hawkish trade advisers began with a speech at an October campaign rally at Madison Square Garden. Lutnick extolled the virtues of tariffs and argued that the duties could at least in part replace the U.