Regulators around the globe began work on replacements for Libor, the London interbank offered rate, well before the U.K.'s Financial Conduct Authority set to put the beleaguered interest-rate benchmark out of its misery. In the U.S., enter the Secured Overnight Financing Rate, or SOFR, a new reference rate being introduced next week by the Federal Reserve Bank of New York in cooperation with the U.S. Treasury Department's Office of Financial Research. The debut of SOFR is a critical step in a quest to wean more than $350 trillion of securities off Li