Investors don't like the deal either. In the four weeks since chief executive Kenichi Watanabe said the acquisition of Lehman's Asian and European franchise would cost Nomura $2bn – a blend of one-off and recurring expenses – Nomura has slid about 10 per cent more than the global banking sector. The shares, down 11 per cent on Thursday, are at their lowest levels since the early 80s.

On a charitable view, however, the deal is not such a stinker. Assuming that a quarter of that expenditure is booked as assets (technology, buildings etc), Nomura's recurring expenses will be boosted by $1.5bn, or close to a fifth, in staff costs. As widely reported, Nomura has agreed to preserve Lehman's 2007 bonus pool. If the average Lehman salary and benefits of $330,000 is simply transferred to Nomura's payroll, the guidance implies that Nomura plans to keep fewer than 5,000 of the 8,000-plus bodies it has brought on board – free of charge.

The deal also signals a shift in approach. Outside Japan, where it remains utterly dominant, Nomura traditionally expanded in two ways: by hiring flashy individuals on a lucky streak and by entering vague referral agreements with corporate finance boutiques. Neither strategy worked. Now, if Nomura can hold on to the relationship bankers it really wants, while building its US distribution, it stands a chance of eventually making the numbers work. Nomura/Lehman is already top five in Asia-Pacific M&A this year and top 10 in equity and debt issues, according to Dealogic.