JP Morgan Chase CEO Jamie Dimon said he is no longer going to discuss bitcoin after much his-publicized criticism of calling the cryptocurrency ‘a fraud’ last month. Noted bitcoin critic and Wall Street banker Jamie Dimon has been known to make dramatic statements about bitcoin, calling it a ‘fraud’ that will ‘get someone killed’. The chief executive of America’s largest bank by assets also said he would fire any employee trading bitcoin for being “stupid.” 
Well it is because he realized that all what he said was nonsense. He will not talk anymore about it since no one would believe in him. And it is all because people just learned that it is part of his style for other people to panic and sell their bitcoins and a great chance for him and his company to buy bitcoins.
A typical banker's move, bail out and call it quits after you got what you needed. I do think that this guys would pose another FUD after a few months to get in and fall silent once more after they finished up buying.