(Reuters) – Bitcoin dropped 7.4% to $40,631.78 at 2205 GMT on Thursday, down $3,248.05 from its previous close. Bitcoin, the world’s biggest and best-known cryptocurrency, is down 15.3% from the year-to-date high of $47,989 set on Jan. 2. Ether, the cryptocurrency linked to the ethereum blockchain network, fell 7.43 % to $2,891.32 on Thursday, down $231.92 from its previous close. (Reporting by Anirudh Saligrama in Bengaluru; Editing by Leslie Adler)