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31 views

Black Litterman: Is it possible to have multiple views (from different sources) on the same asset?

From the basics of Black Litterman I understand that each view on a stock is implemented via the pick matrix P with the expected value of the views in Q. I have read several papers where each stock ...
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66 views

First step of Black-Litterman portfolio

I tried to implement Black-Litterman model. I have a covariance matrix, market capitalization for each asset. I assume a risk aversion factor to be 10. First I use the following code to get ...
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2answers
145 views

Is it possible to deal with non-normal distribution in Black-Litterman model?

Suppose that I know that the normality assumption about my data is unrealistic (as it is very frequently): is it possible to apply any distribution that I judge the right one to the Black-Litterman ...
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1answer
88 views

Systematic Views in Black-Litterman?

Are there any literature on selecting systematic views for Black-Litterman along with methods to specify the uncertainty parameter? For example, rather than specifying a portfolio manager's subective ...
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2answers
309 views

Black-Litterman: Why should the views be independent of each other?

This question relates to this question. In the Black-Litterman framework views of inverstors on the market are modelled. These views have a covariance-matrix $\Omega$. I always found it quite ...
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2answers
272 views

Black-Litterman, how to choose the uncertainty in the views $\Omega$ for smooth transitions form prior to posterior

In Black-Litterman we get a new vector of expected returns of the form: \begin{align} \Pi_{BL} = \Pi + \underbrace{\tau \Sigma P^T[P\tau\Sigma P^T+\Omega]^{-1}}_{\text{correction}}[Q-P\Pi] \end{align} ...
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204 views

Black-Litterman with simple portfolio

In an attempt to learn Black-Litterman I have come across this "simple" example. Suppose that you analyze market data using CAPM $$r_i-r_f=\beta_i(r_m-r_f)+\epsilon_i$$ Suppose there are 2 assets in ...
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1answer
168 views

Is an arbitrary prior for Black-Litterman valid? Or do we need a market implied one?

I went through The Black-Litterman Approach: Original Model and Extensions - see also. The BL approeach starts with a prior on the expected returns vector derived from the hypothesis that the market ...
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3answers
599 views

What is the tau parameter in the Black-Litterman model?

Could someone please provide me with a clear and concise definition of the $\tau$ parameter in the Black-Litterman model? It seems one is rather hard to come by. I understand it to be the 'weight on ...