Japan’s richest man, Tadashi Yanai, lost $1.4bn in a single day on Friday after his company Fast Retailing, which owns Uniqlo, saw its shares crash by 6.7 per cent, according to Independent.

The Chairman and founder of the company suffered the biggest wealth decline among the world’s 500 richest people according to the Bloomberg Billionaires Index.

Uniqlo Japan announced a December slump on Friday, blaming unusually warm weather which it said had hit sales of winter clothing. Overall receipts were down five per cent.

Yanai’s net worth currently stands at $17.7bn, with Friday’s losses causing him to slip six places down the global rich list to 44th.