Are they any good? The simple answer is yes! Several scientific studies by leading universities in the United States such as Stanford, have shown that ANNs can give a distinct advantage over both experienced human stock traders and Expert Systems. In these studies, the neural networks are trained on past price changes in the stock market or currency market, and then their predictions are compared to subsequent prices to see if the advice they give is valid. It is not generally recorded whether the researchers have made any real money using them, possibly due to the ethical considerations that might arise from such speculation.