Buy-and-hold billionaire Ron Baron told CNBC on Friday "fear is evident" in the stock market, but that should not deter people from investing in stocks.

Speaking from his annual investment conference in New York, Baron predicted the Dow Jones Industrial Average, based on historical moves over decades, will reach 650,000 in 50 years, with an over $500 trillion U.S. economy.

The Dow closed at 26,805.53 on Thursday — about 2% away from all-time highs.

"Everybody is worried about something," Baron said on "Squawk Box." "If you invested in 1969, amidst turmoil in 1969, you would have make 25 times your money."

"I think the 6.5% annual growth [in the market] is going to continue, on average, for the next 50 years, at least," he added, making the point that investors should forget the day-to-day market gyrations and stay focused on the long term.

"People forget about compounding" money over time, he said.

The current stock market is the same valuation as it was in 1969, during turbulent times with "cities on fire" and Vietnam War protests and the Dow trading around 1,000, Baron said.

"The economy then was $850 billion. It's now $21.3 trillion. That's up 25 times," he said. "All you had to do was believe that this country was going to survive and invest then and you would have made 25 times your money."

"I'm thinking the next 50 years is going to be similar to the last 50 years. That would be 25 times your money if you invest now," he said, adding that currently "extraordinarily" low interest rates provide even more incentive to invest.

"Technology is making businesses grow faster," compared with the traditional, capital intensive ways of building physical structures in hopes they will pay off over time, Baron said. "It's making the costs be lower."

The founder of Baron Capital, with $29.6 billion in assets under management, also said, "Knowledge is growing at the fastest pace it's ever grown."

Nearly a year ago, Baron had predicted the Dow would reach 500,000 in a half-century.