Investors who had been holding out hope that Senegal could avoid a default are changing tack, selling its short-dated bonds as they expect losses ahead. The nation’s euro-denominated 2028 bond, which had traded at a premium to its dollar notes for several months, took the biggest hit Tuesday after the government said it would pursue a “debt treatment” under an enhanced version of the Group of 20’s Common Framework as part of a deal for a new $2.2 billion program with the International Monetary Fund. It plunged more than 8 cents on the euro at one point before paring losses.