A year ago, the investment banking world saw its biggest upheaval since the financial crisis with UBS’s rescue takeover of Credit Suisse. Twelve months on, the longer term impact of the deal is becoming a bit clearer – but only a bit. Big questions remain, particularly for the combined investment banking business.

One verdict on the deal might already appear pretty emphatic: since the merger was announced on 19 March, UBS’s share price has soared more than 60% to a post-financial crisis high. Yet investors’ judgement is actually less impressive than it might look.