Efficient Capital Markets The competing investors attempt to adjust security prices rapidly to reflect the effect of new information, although imperfect and unbiased. The security prices that prevail at any times should be an un biased reflection of all currently available information. The expected returns implicit in the current price should reflect its riskEfficient Capital Markets – The competing investors attempt to adjust security prices rapidly to reflect the effect of new information, although imperfect and unbiased. – The security prices that prevail at any times should be an unbiased reflection of all currently available information. The expected returns implicit in the current price should reflect its risk