This guy is playing with BTC volatility! In the first time it had worked, because it had more news speculating and saying ill about BTC. This time, BTC world already understood it's motive for talking ill about BTC, and the value of it didn't fluctuate much. I believe this guy will try to get another strategy now, so he can profit more from the little decreases that happen time to time, or because of news that talk ill about BTC.
Yes, because we investors are matured enough. Jamie Dimon is no longer trusted and completely irrelevant to all of us that's why we are not affected by his bashed on bitcoin. Initially it was effective and he was successful because the price really went down and his company was able to buy huge amount in that dip, but we already found out what they have did, that why today, his words carry no weight anymore about the bitcoin market.