I do believe that AI can execute market trades using statistics and data prediction. But this is not 100% accurate as it also needs human intervention.
Why would an AI need human intervention? Do pilots talk to the birds when they have an issue in their plane?
Maybe he means that there doesn't exist real AI thing. AI can't read news and analyze it, think around it and make predictions according to articles. AI is a machine that can process data but in a different way, it can't think as a human and it isn't that kind of mechanism. There are a lot of hormones, including dopamine, serotonin and others that have a huge impact on our thoughts, attention, focus, cognitive abilities. AI is written by a human, we aren't that developed to be a new gods for artificial intelligences, we are far from it. That's why I agree with him too. In most cases, words like AI, Blockchain and others are just lure for people.