"We just finished earnings season and earnings were pretty good," Fink said. "Despite this huge run up in markets, corporate earnings have kept pace. So I will repeat my view of the world, you need to be heavily invested in equities."
And as people live longer, saving for retirement in a world of low interest rates will push more people into the equity markets as they attempt to generate enough savings for retirement, the BlackRock executive said.
"This is a very large secular change and we're just beginning to see it that people are going to become heavily more invested in equities," Fink said.
He added the average American has only saved about $25,000 toward their retirement. Not only will they need to work longer, but it creates societal pressures as younger workers may have greater difficulty in finding a job as fewer older workers retire.
If workers, companies, governments and the financial services industry do not start focusing on long term needs, people are not going to have an adequate amount of retirement savings, Fink said, and "it's going to be a huge societal burden."
(Read More: Save for Retirement Even When You Earn Little)
Earlier, Fink told students and faculty and NYU Stern School of Business that "longevity is the defining challenge of our age."
He said the traditional mix of retirement funding from Social Security, pensions and personal savings was in the grip of "a systemic crisis that is threatening not only retirement systems but also our economic futures."
For savers, Fink told CNBC, "Equities are the asset class that is going to help you earn that return over a 30 year cycle" so you have the savings to retire.