Change in estimated net worth while in office, by president
Forbes's estimate of net worth on inauguration day against the day the president left office, or the latest figure for a term still running. Of the six, only Donald Trump is on Forbes's billionaire tracker, so only his two terms can be drawn on one like-for-like basis: down about $1.2 billion in the first, roughly flat so far in the second.
The other four
None of the four is a billionaire, so none is on Forbes's tracker and there is no matched pair of start and end figures to draw. Their fortunes were counted in millions, not billions, too small to register on this scale. What Forbes has reported:
Clinton (1993–2001): left office in 2001 “not only dead broke, but in debt,” in Hillary Clinton's words, because of his legal troubles.
Bush (2001–09): already a millionaire when elected; his fortune “apparently shrank while in office, according to his financial disclosures.”
Obama (2009–17): the Obamas made $10.8 million in income over the eight years, $3.1 million of it presidential salary, with earnings falling as book royalties declined; Forbes put his net worth at about $6 million in 2012.
Biden (2021–25): Forbes estimated about $8 million in June 2021, five months into the term.