Yeah I don't usually watch his videos but that one caught my eye, since I was aware he has been a practicising fund manager with quite large amounts under management (billions), so he is 'in the trade', so to speak. It's not like listening to the opinions of joe bloggs down the pub, it's a fairly safe assumption that he has at least got some idea of what he is talking about. I'm pretty sure he knows more about investing than I do, anyway.
Of course by the time this kind of message goes out on a public channel like youtube, the goose is already totally cooked. The time to get in was 2 or 3 years ago, and the time to get out has probably already passed.