WASHINGTON—Treasury Secretary Timothy Geithner and Federal Reserve Chairman Ben Bernanke unveiled a new $100 bill equipped with two new security features. The bill will go into circulation Feb. 10, 2011. The Fed, along with the Treasury Department, the Bureau of Engraving and Printing and the U.S. Secret Service, "continuously monitor the counterfeiting threats" for each denomination and redesign decisions are made based on those threats, Mr. Bernanke said.