A global pandemic might not seem the best moment to try to sell ultra-pricey trainers, least of all when the global economy is predicted to shrink 5 per cent this year.

But next week Christie’s, the auction house, will conduct a cyber auction of a dozen pairs of Michael Jordan’s old shoes — and the top lot is expected to fetch $350,000 to $550,000. This follows a digital auction organised by Sotheby’s in May of the basketball star’s old Nike Air Jordan 1s. They fetched $560,000 — a record in the second-hand sneaker world, and a level that might make even billionaires feel dizzy.

The projected Jordan price partly reflects idiosyncratic factors: the ESPN documentary The Last Dance has reinvigorated mania around the star this year. But it also symbolises a bigger trend. Amid the Covid-19 economic pain, some luxury niches are still booming — and asset prices are jumping in unexpected ways. This is hard to track with precision. The luxury sector is opaque, and activity is doubly hard to measure now that spending is becoming more discreet and migrating into new areas.