JP Morgan didn't FUD against Bitcoin, Jamie Dimon did, but it was his personal opinion and not an official statement of the company.

JP Morgan didn't buy any big amount of coins to hodl them, because they believe in Bitcoin, they bought some Bitcoin-based derivatives to speculate on them.

JP Morgan wanted to create their own coin, a stablecoin like Libra, which would make them a competitor of Bitcoin, at least in some sense.

There's no solid proof that institutions buy Bitcoin after spreading FUD, it's just a conspiracy theory.