The common approach for constructing factor mimicking portfolios is to go long in assets with high loadings and to short-sell those with low loadings on some background factors. As a result portfolios containing stocks with low loading on the background factor receive negative betas against the...

We employ the optimal orthogonal portfolio approach to investigate if the size and book-to-market effects in US data are related to risk factors beside the market risk. This method enables us to estimate the upper limit of the risk premium, due to observed as well as all possible unobserved...