摘要：The Cardinality Constraint-Based Optimization problem is investigated in this note. In portfolio optimization problem, the cardinality constraint allows one to invest in assets out of a universe of N assets for a prespecified value of K . It is generally agreed that choosing a “small” value of K forces the implementation of diversification in small portfolios. However , the question of how small must be K has remained unanswered. In the present work, using a comparative approach we show computationally that optimal portfolio selection with a relatively small or large number of assets, K , may produce similar results with differentiated reliabilities.
