Ageing will translate into long run trends in supply as well as demand of capital in the next decades. This paper provides some quantitative assessments of the effects on financial markets of ageing in four large OECD countries (United States, Japan, Germany, and France). Using a simplified general equilibrium model with overlapping generations, it suggests that ageing could bolster capital-labour ratios and lower interest rates in the future (by 25 bp to 100 bp in the long run, depending on the characteristics of pension systems reforms). In this context, the fear for a future “asset meltdown” due to ageing is probably overstated. The model also suggests that the individual accumulation of capital is likely to increase in the future and require structural changes in financial markets. Households will increasingly need to insure against the uncertainty related to future asset prices, rates of return on capital or individual longevity....