Can I ask? Who's Jamie Dimon?
jamie dimon is just another average joe , like warren buffet and charlie lee and other popular names on the internet that keeps on bashing the bitcoin because they are anti bitcoin and uses another type of coins or altcoins. they want bitcoin to go down thats why they always keep on making news that bitcoin is a bubble, bitcoin is a tulip, bitcoin will crash, etc.. and sometimes they are quite annoying.
I don't think Dimon wants Bitcoin down for the long term. We all know how he loves to make disparaging remarks about Bitcoin in public. We then found out that JPMorgan bought a lot of Bitcoins after the dip, and Dimon got accused of market manipulation. He currently has a lot to lose if Bitcoin plunges, unless he's planning on buying some more.
It's not going to work anymore though, since the world has gotten smarter. He's a fraud and his statements regarding cryptocurrencies should have zero credibility.