Richard Thaler on the retail investing boom

Part of what is going on right now is what I call the "bored market theory."  Especially at the beginning of the pandemic, there was almost nothing to do because of the lockdown measures.  There wasn't even any sports on TV because all games were canceled.  So there was nothing to bet on, which is why a lot of people started investing in stocks. 

An important development in this regard preceded the pandemic, at least in the US. It had to do with something that shouldn't really matter in a rational world: free trading...  People like it when something is free.  The combination of free trading and boredom has rekindled interest in investing, especially at the level of individual stocks.  In contrast, a mutual fund or - even worse - an index fund is dead boring.  The entertainment value is practically zero.

~ Richard Thaler, "'Everyone thinks they are a particularly clever investor'," The Market, July 26, 2021