The Vanguard chairman emeritus flew into the UK from his home in the United States to talk about the importance of trust.
This session covered client-first mentality and the importance of trust and client loyalty from a business perspective.
He started by telling delegates: "A relationship without trust is like a car without gasoline."
He then went on to talk about how he believes baby boomers will be the biggest clients of Financial Planning in the next few years.
He said: "Baby boomers will be the biggest consumers of trusted financial advice in history."
This provides a "tremendous opportunity" for advisers to gain a new client base.
He later remarked the current period is the best time to be a Financial Planner.
"You have the best tools at your fingertips, the best tools, best products and best technology."
He also said that the "best advisers behave the way the rules are written."
The session was worth one CPD point in professionals standards and compliance.
Mr Brennan is the chairman emeritus and senior adviser for conference sponsor Vanguard. He joined Vanguard in 1982 and has since worked as president, chief executive and chairman of the board.
Mr Brennan is the first of four keynote speakers over the event, the other three are Dan Sullivan from Strategic Coach, Nick Murray from The Nick Murray Company and Mike Harris, founder of FirstDirect and Egg.
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