Which of the following are the three forms of market efficiency?

The three forms of market efficiency are weak, semi-strong, and strong. These classifications stem from the Efficient Market Hypothesis (EMH), which asserts that asset prices reflect all available information.

• Weak efficiency maintains that all past trading information is already accounted for in stock prices, suggesting that technical analysis cannot consistently achieve superior returns.

• Semi-strong efficiency posits that current stock prices reflect all publicly available information, meaning that neither technical analysis nor fundamental analysis can yield excess returns, as all relevant data is already integrated into the prices.

• Strong efficiency extends this concept by stating that all information, including insider information, is fully reflected in stock prices. Consequently, even insiders would not be able to consistently achieve better performance than the market.

These definitions help in understanding how different types of information impact stock prices and the implications for various investment strategies. The other option choices do not represent standard economic or finance concepts related to market efficiency, which reinforces why they do not apply here.