Conflicting realities in the US private equity industry at the end of its busiest year on record were on display in two strikingly different settings on Tuesday.

There was a sense of accomplishment at a Sotheby’s auction in New York, where David Rubenstein, the co-founder of Carlyle, used $21.3m (£10.7m, €14.8m) of his wealth, partly accumulated during the buy-out boom, to purchase a 700-year-old copy of the Magna Carta.