I have a trading strategy which provides me with a list of candidates (stocks) for rebalancing my portfolio. I have also a list of stocks in my portfolios and I need to select which stocks from the candidates list will be added to the portfolio knowing that the portfolio has a maximum in term of number of stock and that the portfolio should respect some constraints.
Basically, a score is computed for each candidates. The same score exists for all position in the portfolio. The optimization should therefore be done by selecting a new portfolio containing the best stocks based on this score (current stocks in the portfolio and candidates) and fulfilling the constraints (historical vol, sector allocation,etc..).
I would like to know what is the best optimization technique to answer such question?