Over the past several months, non-fungible tokens, or NFTs, have rapidly evolved to be a phenomenon in the world of crypto assets, where things often tend to be something of a rollercoaster ride.

With digital items ranging from a tweet to art works sold for staggering sums — sometimes millions of dollars — a good number of people may be thinking that this is set to be another one of those turbulent rides.

The latest figures suggest that the bubble may have already burst, as weekly NFT sales have plummeted by more than 90% compared with their peak in early May.