Macy’s Inc.’s debt was cut to junk by Moody’s Investors Service after the second-largest US department-store chain’s operating performance deteriorated. Ratings on Macy’s senior unsecured notes were cut two notches to Ba2 from Baa3, bringing them two levels below investment grade, Moody’s said in a statement yesterday. The downgrade comes a day after Macy’s wrote down the value of its assets by $5.4 billion to reflect the decline in its stock price, and follows Moody’s decision yesterday to cut JCPenney Co.’s debt to junk status.