Dennis Gartman, editor of the Gartman Letter for 30 years before recently calling it quits, laments that the current environment is a “kids market,” run by investors who haven’t experienced a bear market that will soon arrive.

“(It will) do real and perhaps severe damage to portfolios everywhere,” Gartman warned of the coming bear market in a recent interview with Barron’s.

Gartman ended the publication of his newsletter on Tuesday after 30 years of publishing. While he may not be as well known to individual investors, he has been a valuable resource on Wall Street.

He said he thinks the absence of fear in the markets, not any geopolitical events or action by U.S. President Donald Trump (who Gartman fully supports for a second term), will send the markets into a tailspin.

He references George Goodman’s classic book “The Money Game” in using the term “kids market” to describe the investors who are making the most money during this record-long raging bull market that has lasted over a decade now.

“(These kids are) young, brash, utterly naive, ill-educated, egregiously overconfident, neophyte-yet-fearless investors,” Gartman said, while arguing that all market veterans can do is wait and be “fearful yet envious” of the profits being made by the younger generation.

But it won’t last, Gartman thinks. He’s been in a few similar kid markets, and none of them have had a happy ending, which he’s confident will happen again. The “all-too-easily-made profits (of today’s) kids will evaporate.” And the outcome will produce some older, poorer-but-wiser investors.

Gartman went on to say that education doesn’t beat experience, and that means he can’t trust “a 26-year-old who has just gotten his MBA and has no experience.”

The best advice he has for choosing an adviser is: “Don’t follow anyone who hasn’t been around for at least an entire cycle.”

Gartman doesn’t pinpoint when a bear market will actually arrive, and he doesn’t think it’s crazy to see investors continue to push the markets higher. By looking at all aspects of major markets, he doesn’t see reward outweighing the risks in stocks.

During his long career analyzing Wall Street, Gartman, 69, thinks a lot of his success has come from taking a broader, more contratian view of the markets. He argues you don’t have to be the best at analyzing one sector of the market, but only decent at breaking down many different sectors.

“People who traded foreign currencies weren’t talking to those who traded oil, who in turn didn’t talk to those who traded bonds or equities, and so forth,” Gartman said. “(No one was) focusing on the interconnections between the various markets.

“I am the liberal-arts major on Wall Street.”

And where does Gartman see future value? Commodities, and especially agricultural commodities like cotton and wheat are “unbelievably inexpensive right now.”