A portfolio diversification index is defined as the ratio of an equivalent number of independent assets to the number of assets. The equivalence is based on either attaining the same diversification benefit or spread reduction. The diversification benefit is the difference in value of a value...

Market efficiency is measured by arbitrage proximity. The magnitude of probability distortion necessary to remove drift calibrates the efficiency. Simulations of bilateral gamma models estimated on a year's past returns yield empirical acceptability indices for each day for each asset. The...