Some dealers could issue a stack of complex, credit arbitrage-based debt without anyone batting an eyelid – BNP Paribas, Citigroup and Credit Suisse, for example, are all big players in what are known as skew notes.

But Mediobanca? The 5,000-employee investment bank is said to be among the market’s top five skew note players, issuing at least €1.62 billion ($1.83 billion) since 2016 – equivalent to nearly a tenth of the Italian firm’s bond funding.

The bank is tight-lipped about the business