Which form of market efficiency claims that prices reflect all past price and volume data?

• A. Semi-strong efficiency
• B. Weak-form efficiency
• C. Strong-form efficiency
• D. Efficient-market hypothesis

Answer: (B)

Prices reflecting all past price and volume data is the weak-form of market efficiency. In this form, all historical trading data is already reflected in prices, so trying to profit from chart patterns or other technical signals based on past prices and volumes isn’t expected to consistently beat the market. By contrast, semi-strong efficiency says prices reflect all publicly available information, and strong-form includes even insider information; the general Efficient Market Hypothesis is the broader umbrella concept.