Investor's wiki

Black-Litterman Model

Black-Litterman Model

What Is the Black-Litterman Model?

The Black-Litterman (BL) Model is a scientific device utilized by portfolio managers to enhance asset allocation inside an investor's risk tolerance and market sees. Global investors, for example, pension funds and insurance companies, need to choose how to dispense their investments across various asset classes and countries.

The BL model beginnings from a neutral position utilizing modern portfolio theory (MPT), and afterward takes extra contribution from investors' perspectives to decide how the ultimate asset allocation ought to veer off from the initial portfolio weights. It then, at that point, goes through a course of mean-variance optimization (MVO) to boost expected return given one's objective risk tolerance.

The Basics of the Black-Litterman Model

The Black-Litterman model for portfolio construction depends on modern portfolio theory (MPT). Modern portfolio theory places that an investment's risk and return attributes ought not be seen alone, yet ought to be assessed by what the investment means for the overall portfolio's risk and return. MPT demonstrates the way that an investor can build a portfolio of different assets that will boost returns for a given level of risk.

Moreover, given an ideal level of expected return, an investor can build a portfolio with the most reduced conceivable risk. In light of statistical measures, for example, variance and correlation, an individual investment's performance is less important than what it means for the whole portfolio.

The BL model was intended to develop this model since one of the limitations of MPT is that it accepts that past expected returns will go on into what's to come. Other pricing models — for instance, the capital asset pricing model (CAPM) — nonetheless, may create unexpected expectations in comparison to that of the past performance. The BL model integrates noticed market data alongside investors' projections of future expected returns, in view of models like CAPM or others. The model basically changes the default MPT allocation by considering expectations of future performance.

The BL approach permits any model assessment mistake to become apparent as allocation decisions might amplify poor assumptions.

Special Considerations

The BL model has been around starting around 1990, and it gets a great deal of respect from the institutional investment community. It was made by Goldman Sachs financial analysts Fischer Black (of Black-Scholes model notoriety) and Robert Litterman.

While the BL model apparently improves the asset allocations given by MPT by consolidating conclusions on future outlook, in light of the fact that these projections are just suppositions or the aftereffect of pricing models that depend on subjective data sources, the BL model might bring about bias or erroneous assumptions. For example, an excessively hopeful perspective on one asset class will bring about having greater portfolio weight than MPT would suggest, and on the off chance that that asset class vacillates can bring about amplified losses. Investors using the Black-Litterman model ought to know about this and update their expectations consistently, rebalancing their portfolio weights in like manner.

An Example of the Black-Litterman Model

Expect that a portfolio management team at a certain insurance company is very bullish on non-industrial nation markets in the year ahead. The initial asset allocation to emerging markets coming about because of modern portfolio theory is 10%. Subsequent to affirming their viewpoints with different pricing models and economic outlooks for the region, they are leaned to overweight emerging markets stocks.

In the wake of placing this bullish view into the BL model, they perform mean-variance optimization and permit their portfolio to contain up to 15% emerging markets securities.


  • The MPT model supposedly is limited in that it just consolidates historical market data and afterward expects those equivalent returns going ahead.
  • The Black-Litterman Model is a portfolio allocation model that starts with modern portfolio theory (MPT) and includes investor perspectives on expected returns.
  • The BL model lets the investor applies their own perspectives and afterward streamlines the suggested asset allocation.