Joseph Perella remembers the era on Wall Street in which a $100m bond deal for Gulf Oil commanded the full attention of First Boston, then his employer.

Back in the 1970s, “the firm turned itself inside out for that,” says the founder of Perella Weinberg, settling into his chair over dinner at the timeworn Italian cultural club on Manhattan's Upper East Side where he and Peter Weinberg first discussed building a boutique bank. “It's a different world today.”

Banks' stock and bond trading businesses swelled so much in recent decades that, by the turn of the millennium, a $100m (€71m, ￡61m) bond deal would not have lured today's influential “rainmakers” out of bed. As those revenues overpowered fees generated by traditional advisory work, old-school bankers who had to compete harder for their share of the pie grew increasingly focused on mega-deals.