Behavioral portfolio theory (BPT) is an investment theory that seeks to explain how and why investors make the decisions they do when constructing a portfolio. The theory posits that there are certain behavioral biases that lead investors to make suboptimal decisions, which in turn leads to lower returns.
The key idea behind BPT is that by understanding these behavioral biases, investors can avoid them and thus improve their investment performance.
What are some behavioral biases that have been identified by BPT?
There are a number of different behavioral biases that have been identified by BPT, but some of the most important ones include:
1. Overconfidence
Overconfidence bias leads investors to believe that they know more than they actually do, which leads them to take on too much risk.
2. Anchoring
Anchoring bias leads investors to place too much importance on the first piece of information they receive, and as a result, they may make suboptimal decisions.
3. Herding
Herding bias leads investors to follow the crowd, even when it may not be in their best interests.
By understanding these biases and avoiding them, investors can improve their investment performance. While BPT is not a guaranteed way to achieve higher returns, taking investor behavior into account can certainly help portfolio management and construction.
What’s the difference between behavioral portfolio theory and modern portfolio theory?
BPT and MPT models take very different approaches to portfolio construction. Ultimately, considering both approaches can help investors create portfolios that are tailored to their individual asset allocation needs and preferences.
While there are clear differences between BPT and modern portfolio theory, they can both be used together to create an optimal portfolio, and there’s no silver bullet approach to achieving superior returns in the stock market.
Modern Portfolio Theory
MPT aims to maximize expected returns for a given level of risk, or minimize risk for a given level of return. Modern portfolio theory focuses on expected returns and risk in an “ideal world.” MPT assumes that all investors behave in a purely rational and logical way when making investment decisions and uses quantitative analysis of expected returns and risk based on past performance to construct a diversified portfolio.
Behavioral Portfolio Theory
BPT looks at how investors make decisions in real world scenarios to predict future economic behavior, taking behavioral factors into account, including psychological aspects of trading such as overconfidence, fear of regret, and the disposition effect. Behavioral portfolio management takes peoples individual biases into account, and considers behavioral aspects of trading such as loss aversion, as well as social and economic factors before making an investment decision.
Behavioral portfolio management allows investors to better understand the power of emotions and biases, and how they impact their decisions, and the consideration of social and economic factors can also help investors find opportunities that might be overlooked by MPT-based portfolios.
