The more labour it costs to make a product, the more it is worth, and inversely the less labour it costs to make a product, the less it is worth. Money-prices are at best only an expression or reflection of Marx's value relationships—accurately or very inaccurately. Products can be traded above or below their value in market trade, and some prices have nothing to do with product-values at all (in Marx's sense), because they refer to tradeable objects which are not regularly produced and reproduced by human labour, or because they refer only to claims on financial assets.