Efficient Markets Are Not Always Perfect

An efficient market does not mean the market is perfect.

In real life, markets are usually neither completely efficient nor completely inefficient. They often fall somewhere between these two extremes. Some securities may reflect information quickly, while others may adjust slowly.

Market efficiency depends on several factors such as:

1. Number of investors following the security
2. Availability of information
3. Trading volume
4. Liquidity
5. Transaction costs
6. Speed of information flow

Example:
A large company stock may be followed by 50 analysts and thousands of investors. If new information is released, the price may adjust very quickly.

But a small company stock may be followed by only 2 or 3 analysts. Since fewer investors track it, the price may take longer to adjust.

This means large and liquid markets are generally more efficient than small and less liquid markets.