Family offices are in charge of managing the personal wealth of people or groups of people, themselves already exposed to the ups and downs of their family business. Their role is to add security to their investments, not extra risk, while ensuring that, on the long run, performances meet those of the market in general. They must closely monitor their exposures in order to avoid that they conflate with those that families are already exposed to. An accurate understanding of the risks of each manager they hire, and their reactions to a range of market scenarios, is necessary to anticipate if, under certain scenarios, all the managers will jointly suffer and losses, otherwise uncorrelated, will suddenly add up. Avoiding such nasty surprises is the best guarantee of long-term performances under any market circumstances.