Bank of England governor Mark Carney says public faith in financial markets has been shaken by "widespread misconduct".
Markets have been "tainted" by scandals to an extent that the public now question their integrity, Mr Carney told the BBC.
An "open forum" that includes the public will look at how markets can have "a positive future".
Mr Carney said it was important that all sectors of society had their say.
Chancellor George Osborne and European Central Bank President Mario Draghi are also attending the forum.
Mr Carney said: "Markets lose their social acceptability if they're not viewed as being effective, not working well, that's the first aspect.
"They also lose that social acceptability if they're viewed as not having integrity. If there's a series of scandals, there's a perception of ethical drift.
"There was widespread misconduct in certain parts of markets, which tainted markets more broadly and required a forceful response," he added.