Answer:
1. Stock markets reflect all available information about the value of stocks AND
2. Changes in stock prices are impossible to predict.
Explanation:
The characteristics that are consistent with the efficient markets hypothesis are that
1. Stock markets reflect all available information about the value of stocks
By definition efficient markets are those whose asset prices reflect all available information.
2. Changes in stock prices are impossible to predict.
The efficient market hypothesis has been described as a backbreaker for forecasters. In its crudest form it effectively says that the returns from speculative assets, are unforecastable.