Efficient Market Hypothesis and Active Portfolio Management

Weak form efficiency asserts that asset prices incorporate all past trading information, such as historical prices and volumes. This means that technical analysis, which relies on past market data to predict future price movements, is ineffective for achieving consistent excess returns, as all relevant information is already reflected in current prices.

Under the semi-strong Efficient Market Hypothesis (EMH), all publicly available information, including financial statements, is already reflected in stock prices. Therefore, using this information cannot provide an investor with an advantage to earn abnormal returns, as the market has already adjusted to incorporate this data.

The random walk hypothesis suggests that stock price changes are random and do not follow any predictable patterns. This means that past price movements cannot be used to forecast future prices, making price changes independent of one another. As a result, investors cannot reliably predict stock movements based on historical data.

A key assumption of the Efficient Market Hypothesis (EMH) is that investors act rationally, meaning they make decisions based on all available information to maximize their returns. This rational behavior ensures that asset prices reflect true value, as investors are expected to respond appropriately to new information, leading to efficient markets.

Consistent market-beating returns by some funds suggest that certain investors can consistently identify undervalued assets or exploit inefficiencies in the market. This contradicts the efficient market hypothesis, which posits that all available information is already reflected in asset prices, making it impossible to achieve sustained excess returns without taking on additional risk.

The January effect and momentum anomalies are phenomena where asset prices deviate from expected patterns, suggesting that markets do not always reflect all available information. These irregularities indicate that investors can exploit predictable trends, challenging the Efficient Market Hypothesis (EMH), which posits that markets are always rational and efficient. Thus, they are classified as market anomalies.

Active portfolio managers believe they can achieve higher returns by identifying securities that are undervalued or overvalued before the broader market recognizes these discrepancies. This approach relies on conducting in-depth analysis and research to exploit pricing inefficiencies, thereby capitalizing on potential gains once the market adjusts to the true value of these securities.

In a perfectly efficient market in the strong form, all information, including insider information, is already reflected in stock prices. Therefore, insider trading should not yield abnormal profits. However, the statement is false because in reality, markets may not be perfectly efficient, allowing for the possibility of generating abnormal profits through insider trading.

Cognitive bias refers to systematic patterns of deviation from norm or rationality in judgment, leading investors to make decisions based on emotions or flawed reasoning rather than objective analysis. This challenges the Efficient Market Hypothesis (EMH), which assumes that all investors act rationally and have access to all relevant information.

Efficient Market Hypothesis (EMH) suggests that all available information is already reflected in asset prices, making it challenging for investors to consistently outperform the market. This rationale supports passive investing strategies, which aim to match market returns rather than attempt to beat them, as active management often fails to deliver superior performance.

Market efficiency refers to the degree to which asset prices reflect all available information. In an efficient market, prices adjust quickly to new data, ensuring that securities are always priced accurately. This concept is crucial in finance, as it influences investment strategies and the predictability of price movements based on new information.

Consistently outperforming the market index over a decade indicates that the manager possesses genuine investment skill or that market inefficiencies exist, allowing for such outperformance. In efficient markets, achieving sustained excess returns would be unlikely, suggesting that either the manager's abilities are exceptional or that opportunities for profit exist.