A growing number of studies have called into question the validity of the random walk and efficient markets hypothesis. The occurrence of seasonal anomalies such as the January, Monday and holiday effects, the observation that specific mutual funds continue to outperform or underperform a market index, and the finding that technical trading rules can predict price movements, all constitute violations of the random walk and/or the efficient markets hypothesis. Many of these studies assess whether, after adjusting for transactions costs and possibly risk factors, systematic profits can be made. The results on profitability are mixed, with some studies concluding that profits can be made.