Skip to main content
3 votes

What is the meaning of Beta of an individual asset in relation to a portfolio, not the market?

Not directly answering your question, but is this theoretical or did you actually do this? If so, I hope you do know that beta is not stable over time, only measures a linear relationship and that the ...
AKdemy's user avatar
  • 9,144
2 votes

Optimal weights in portfolio after rebalancing

It depends what your optimization problem is. The simplest would be return maximization: $$\max_{w \geq 0} w^\top x \text{ subject to } \mathbf{1}^\top w$$ This is a standard linear program, and the ...
msantama's user avatar
  • 151
2 votes

Asset rate (elasticities ?) of substitution

Your language needs to be more clear. What do you mean by a shock to asset 2? A decrease in price of asset 2, should not change your allocation and have no spillovers (since the expected return of ...
phdstudent's user avatar
  • 8,441
2 votes

"Risk Matters Hypothesis" - does it really?

I didn't read the referenced paper, but I did try to replicate your numbers. I agree with your calculations for the individual Sharpe ratios for the two portfolios. However, I do not agree with your ...
AlRacoon's user avatar
  • 6,642
2 votes

How do I show that there is no tangency portfolio?

Any point on the efficient frontier is the sum $$ Z +\lambda X, \qquad \lambda\in\mathbb{R},$$ where $Z$ is the minimum variance fully invested portfolio and $X$ is an efficient zero-cost portfolio. ...
Iron Soles's user avatar
2 votes

Interpretation of optimal weights in portfolio for risk-adjusted return maximization

With regards to your question about the denominator, if we expand the denominator, it becomes: \begin{equation} w_1 = \frac{\mu_1\sigma_2^2 - \mu_2\rho\sigma_1\sigma_2} {\mu_1\sigma_2^2 - \mu_1\rho\...
KaiSqDist's user avatar
  • 1,564
1 vote

How can this problem be defined formally?

The event that the second stock price is less than a constant $K$ at the time $h$ is mathematically described by $\{S_2(h)< K\}$. The first stock price, at the time $t\in [T,H]$, given the event is ...
NN2's user avatar
  • 1,033
1 vote

Reverse optimization: How to generate the expected portfolio returns given the weights and a series of constraints on those weights?

This is not yet an answer, but too long for a comment. Let's start without the box constraints and solely impose $\sum_iw_i=1, i.e. w^T\mathbf{1}=1$: $$ \begin{align} \max_w\quad & w^T\mathbf{\mu}-...
Kermittfrog's user avatar
  • 6,927
1 vote

Help me understand super replicating portfolio

I'm not familiar with super-replicating portfolios, but what I've gathered is that the idea is to find a static hedge that is greater than or equal to the asset with probability 1, ie find $a, b$ such ...
Rylan's user avatar
  • 635
1 vote

Value-at-Risk of a portfolio with a stock after recent IPO

You may be able to use a multi-factor model for the VaR, if allowed by whoever needs to approve/validate your VaR methodology. In summary, assume that there are a only few indices, and that every ...
Dimitri Vulis's user avatar
1 vote

Standard deviation of large equal-weighted portfolios

This is incorrect at the step where you evaluate the double summation: $Var(R_P)=\sum_{i=1}^n\sum_{j=1}^n\frac{1}{n^2} Cov(R_i,R_j)$ You then have to consider two cases $i=j$ and $i \neq j$. For $i=j$,...
Hans-Peter Schrei's user avatar
1 vote

Why not inequality constraint in mean-variance portfolio optimization?

I'm not sure if I understand your question correctly. I'll try to answer, but you ay want to clarify what you're asking. I'll review portfolio optimization and constraints. Typically, you have a ...
Dimitri Vulis's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible