Weighting with restrictions, but no clear objective function?

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Here is the problem:

I have 40 shares in an index and I want to weight them based on their market value, define the known value as $x_i$

In the traditional way, the weight of each share is calculated as:

$w_i = x_i / \sum^M_{j=1} x_j $ for $M = 40$

However, now I want to apply the following restrictions:

  • $w^{k}_s <= 0.05$
  • $\sum^{N_k}_{s=1} w^{k}_s <= 0.10$ for all $k = 1...K$
  • $\sum^{K}_{k=1} \sum^{N_k}_{s=1} w^{k}_s = 1$

Moreover, each share belongs to one sector $k$, the sum of the weights of the shares within each of these sectors should be less or equal to 0.10. In addition, the weight of each individual share $i$ should be less or equal than 0.05. Summing up all the weight $w^{k}_s$ should add up to 1.

My questions are:

  • How to solve this?
  • What is the solution?
  • Is there an objective function and what is it?

Many many thanks!