> Market valuations for tech companies have been irrational for years No they weren't, unless by "years" you men 2-3. Google, Facebook etc were expected to gro

> Market valuations for tech companies have been irrational for years No they weren't, unless by "years" you men 2-3. Google, Facebook etc were expected to grow and they did grow to match those valuations, they weren't overvalued. When you know a market will grow then you price that in. Some companies don't grow as expected, but most do, the market is usually pretty good at estimating.