When four JP Morgan banks analysts, led by Carla Antunes da Silva, handed in their notice on Tuesday February 15, word spread quickly. Within 48 hours, the departures were seen as “a problem” to JP Morgan’s hopes of running the flotation of some Spanish savings banks, people involved in the situation said.

Ever since 2003 when New York attorney general Eliot Spitzer ruled that bank departments should be separated by Chinese walls in order to avoid conflict of interest, firms have been forced to ensure their research is independent of the investment banking units. This left equity research divisions solely dependent on trading commissions.