Offer your thoughts or opinion on the input financial query or topic using your financial background.

What evidence exists for claiming that you cannot beat the market?
The reason for this is arbitrage. In an free and open market, investments that are certain to generate above-average profits would do so by being sold cheaply, while having a high return on investment after that. But in a free market, prices are set by supply and demand. There is a high demand and little supply for investments that would certainly outperform the market. The demand is in fact so high, that the purchase price rises to the point of eliminating that excess return. And with high-frequency automated trading, that price hike is instant. But who would even want to sell such guaranteed outperformers in the first place? Of course, there are uncertainties associated with stocks, and individual stocks therefore move independently. As "the market" is an average, some stocks will therefore beat the market over certain time periods. That's random statistical variation. The only realistic path to above-average returns is to accept higher risks. As discussed above, nobody wants to sell you safe bets. But risky bets are another matter. Different actors will price risk differently. If you aren't worried much about risk, you can pick up stocks that are cheap by your standards. That is possible only because such stocks aren't cheap by risk-averse standards.  Looking a bit deeper, we see that arbitrage works in a free market because there's essentially perfect information. But risk is precisely the absence of such information, and that can lead to price variations. Yet, as the lack of information means a lack of certainty, you can't use this to reliably beat the market.