U.S. Supreme Court Justice Samuel Alito Jr. has recused in several important cases recently, leaving some lawyers involved scratching their heads — or wondering if he has recently expanded his investment portfolio.

His most high-profile recusal this term came Oct. 9 when the court’s orders list stated Alito took no part in the denial of review in Chevron v. Naranjo, a long-running effort by Ecuadorean natives to seek damages from Chevron for causing extensive pollution in their region.