Does 'market timing' (buying low and selling high) work?

Market timing is a strategy of deciding when to buy and sell by predicting the future direction of the market as a whole, but many point out that short-term stock market returns are almost impossible to predict.

Some analyses also suggest that 'return-chasing' behavior, buying funds with high past returns and selling those with low returns, can actually hurt performance. You should also consider that frequent trading increases costs.