Musk’s Fate in Lawsuit Over SolarCity Deal Likely Clear by April

The judge deciding whether Elon Musk will lose billions of dollars in a shareholder lawsuit challenging Tesla Inc.’s $2.6 billion acquisition of a solar power provider said he would rule in about three months.

Delaware Chancery Court Judge Joseph Slights III offered the estimate at closing arguments Tuesday, six months after the electric car maker’s chief executive officer testified in a trial over the 2016 purchase of SolarCity. At the heart of the case is whether Musk improperly used his influence with Tesla’s board to get the transaction done.

If he loses, it could cost him some $13 billion, ...