Before revision: Since Bachelier  in 1900 , when mathematical finance began, attempts at understanding the nature of stock market prices and at predicting them have not succeeded. Statistical models have only found minor regularities and anomalies.
After revision: Since Bachelier in 1900 , when mathematical finance began, attempts at understanding the nature of stock market prices and at predicting them have failed. Statistical methods have only found minor regularities and anomalies.