Shares of closeout retailer Big Lots Inc. fell on news that federal officials are investigating stock trades by chief executive Steven Fishman. In an SEC filing, the Columbus, Ohio, company said it had received a grand jury subpoena from the US attorney for the Southern District of New York requesting information on Fishman’s trades. Also, The Wall Street Journal reported that officials were looking at whether Fishman had sold $10.3 million in stock based on knowledge of upcoming negative corporate news.