U.S. stock markets will remain closed on Jan. 9 in honor of former President Jimmy Carter, continuing a long-held Wall Street tradition in mourning the nation’s leaders. Both the New York Stock Exchange and Nasdaq announced this week that they plan to close their equity and options markets next Thursday in observance of a National Day of Mourning for the 39th U.S. president and global humanitarian. Carter died on Sunday at his home in Plains, Georgia.