Knight Frank's Prime Global Cities Index rose 4.8% over the 12 months through to March 2018, compared to a year earlier. But the index averaged out the drama playing out on the ground: In some cities, luxury prices skyrocketed, and in other cities prices dropped sharply.

Seoul ranked number one on the index, with luxury house prices soaring 25% over the 12 months through March. Berlin came fourth on the list, but first within Europe, with annual price growth of 10.9%. The index considers “luxury” those sales whose prices are in the top 5% in that market.

London prices fell by 1.1% over the past 12 months but at the bottom of the list of 43 top global cities was Stockholm, where luxury house prices have dropped by 8.4% over the past 12 months, with price drops accelerating: over the past six months alone, prices have fallen 9%. This is despite the Swedish base rate remaining in negative territory at -0.5%.