That doesn't make them wrong. It's basically just a tautology. If you believe X is a great investment, and you aren't investing in it, that would be a far stranger situation.
>"Don’t Tell Me What You Think, Tell Me What You Have In Your Portfolio"
(I'm not sure whether I agree with the point, but I think that is the point Taleb was making.)
Far stranger schemes exist, the most recently to hit popular culture is gamma squeeze. Just because a scheme is strange has little bearing on whether or not it'll end up working out with them having your money.
At the end of the day, the point is they're trying to sell their book, which is not the same as trying to sell investment X (although they may be very closely related).
Or most recently Gamestop investors.
> At the end of the day, the point is they're trying to sell their book, which is not the same as trying to sell investment X (although they may be very closely related).
My point it is almost never going to be possible to distinguish between good investment advice and self-serving investment advice. Sure, there is some fungibility there for people with different investment needs, like pension funds vs young income earners. But! we should think about what we would think if the reverse was true. If investors were advocating for investments that they weren't personally invested in, then I would be far more skeptical than if they did.
We should be skeptical of all investment advice. For a specific fact to make us more skeptical of investment advice, we need to consider the alternative where that was not true. I don't see situations where large investors advising people to put money not where their mouth is gives someone more confidence in their advice.
One example: I recommended real estate rentals through the 2008-2015 range to several friends despite having none myself. Why? Because it was possible for them to generate significant leverage otherwise unavailable to them and they were in a much better position than me to work the second job of being a landlord.
Most other industries have a clear separation between the people who make and sell the product, and the people who publicly opine on the product.
Film journalists aren't film makers, car journalists aren't car makers, games journalists aren't game makers. And if the CEO of EA Games announces the next Madden game is their best ever, you'd take that with a pinch of salt.
Of course, conflict-of-interest-free journalism ain't exactly a growth industry these days, so this probably isn't the model of future stock tips.