There is a contrast and similarity between founder companies and themes. The founder company exemplifies the implausibility that an idea will succeed. If it were universally accepted, many entrants would likely compete and reduce returns. It should have a commercial idea that others won’t invest in. Many fail. Themes don’t follow the same rhythm. These are widely recognised trends that today become ETFs and attract momentum-following investors.

The similarity is in their valuations. Founder companies, according to a Harvard Business Review study, tend to be overvalued as they enter public markets and on aggregate don’t offer excess returns in subsequent years. Nor do themes.