Buying a house is not like losing your job, you're not supposed to put all your money in risky investments if you know you're going to need it in less than 5 years (for retirement, to go on extended unpaid leave, to buy a house, etc.).

But even for longer time horizons, I think the common wisdom that stocks are low risk over a long planning horizon is overblown: https://web.archive.org/web/20170911171611/http://www.norsta...