According to him the 7% to 10% that you get from investing in the whole market is too conservative and you would get 15%+ conservatively if you invest in a tech index or fund. And if you invest long term the risk difference is minimal.
I then tried to come up with scenarios in which tech would implode, but I honestly don't find those plausible. The US gov would certainly step way before that point, as a last measure of resort.
I'd be interested in hearing your opinions.
If you might want to retire soon and start spending your money to support yourself, then "investing for the long term" is not sensible. You need stability, not an extra 5% that comes with a risk of a bubble popping. On the other hand, if you have enough money to live on outside of these investments, and are just trying to make higher numbers appear on statements but it would not harm you in the slightest if those numbers crash for 5 or even 10 years... then sure, it probably is sensible.
Most people fall somewhere in the middle, and want diversified investments so that if one piece crashes, the others hold up, and you get a return that is in the middle, with a risk level in the middle.
Coming up on 3 decades of the stock market being utterly irrational about Tech" doesn't mean the world is just this way now. It means the reality is going to hurt when it hits.