The rules of supply and demand are straightforward. Online marketplace Alibaba knows this. As founder Jack Ma and his team travel the world talking to mobs of would-be buyers for the company’s American depositary shares, the offer price is rising. A $2 move (worth about $5bn in market capitalisation) is unlikely to shift the demand curve much. The deal was probably sold before “hello”.

While some prepare to pay up, others enjoy the fruits of their prescience. Yahoo will sell 5 per cent of Alibaba’s enlarged share capital, over one quarter of its holding, to realise as much as $8.2bn. But Alibaba’s largest shareholder has been quiet. SoftBank, which owns more than one-third of the company, will not be selling any shares. At the new price, the stake for which chief executive Masayoshi Son paid $20m in 2000 is worth more than $50bn.

That sum could be very handy. SoftBank’s balance sheet has been stretched since its 2013 acquisition of US mobile telecom operator Sprint. Net debt as a multiple of earnings before interest, tax, depreciation and amortisation is still far from previous peaks, at three times. But SoftBank’s interest bill is well over double the previous peak (of Y115bn) in 2008. Interest cover (earnings before interest and tax as a multiple of interest expense) expense has collapsed from 12 times in 2013 to just over three times this year, according to S&P Capital IQ data.