[corethree]

>To test whether markets are perfectly efficient, just look for large movements over time. If a stock goes up 20% in a year, the market might have undervalued it last year, or is overvaluing it this year. It's unlikely the it was correctly valuing it at both times. In the absence of a Covid-19 pandemic, act of god, etc. of course.

This is technical analysis not value investing.

[spfzero]

It's not the investment thesis, it's a thought experiment to test market efficiency. It's a test to see whether markets are always efficient, and to me demonstrates that they are not, and that value investing might be an interesting thesis to pursue still.

People have been saying for decades that value investing is not possible since the market is too efficient. My point is that it is not efficient enough to prevent value investing from being a successful strategy.