Financial advisor was a title on Ferenginar for a person who advised the Grand Nagus in financial matters.
While talking to Quark in the Chamber of Petitioners on Ferenginar, Grand Nagus Zek announced Quark as his new financial advisor. Later he told Zek that all of his advice came from his moogie, Ishka. (DS9: "Ferengi Love Songs")
Ishka continued to be Zek's secret financial advisor. (DS9: "The Magnificent Ferengi")
When Ishka was unavailable, Zek "created" Lumba, another female Ferengi advisor, to meet with Brunt. (DS9: "Profit and Lace")
The position of the financial advisor was offered to Quark for a second time when Rom was named new Grand Nagus. (DS9: "The Dogs of War")