KBW LLC, a Stifel company, operates in the U.S. and Europe through its broker dealer subsidiaries, Keefe, Bruyette & Woods, Inc. and Stifel Nicolaus Europe Limited ("SNEL"), also trading as Keefe, Bruyette & Woods Europe ("KBW Europe").
In the context of the input sentence, determine the relationship between 'Stifel' and 'broker'.
Options: product/material produced, business division, location of formation, chief executive officer