[csantini]

The market is like an ecosystem. There are huge mammals (investment banks, hedge funds) that look at certain type of preys, and there are smaller rodents that only eat very tiny worms.

In high volatility regimes, ie. stocks with low market cap, the market is far from efficient. Hedge funds are not even looking at stocks with 100M market cap.

There are traders that act in these regimes that beat the market, exactly because they play small.

Anyhow most people would be better of by assuming the market is completely efficient.