JPMorgan Chase & Co. CEO Jamie Dimon warned Monday that the current financial climate and banks doing “stupid things” like taking on risky loans could lead to a market meltdown similar to the one before the 2008 financial crisis.

“At some point there will be a cycle. I don’t know what confluence of events will cause that cycle to occur,” he said. “My anxiety is heightened by that. I’m not reassured by the fact that asset prices are high. In fact, I think it increases the risk.”

Dimon said in remarks to investors Monday that market conditions, including record levels, could be a cause for concern.

“Unfortunately, we saw much the same situation in 2005, 2006 and 2007. A rising tide lifted all boats. Everyone was making a lot of money. People were making the most of it. The sky was the limit,” he said.

“And today, I think the rising tide is lifting all boats. My own view is that people are starting to get a little bit more comfortable that this is the reality, that we have such high asset prices, such high volumes, and that we’re not going to have any problems,” he said. “I don’t know how long things are going to be great for everyone. I see some people doing stupid things.”

Mr. Dimon did not say which institution he was referring to, but he assured investors that his bank, the nation’s largest, is “pretty prudent,” adding: “We play by our own rules.”

He also said recent concerns among investors about artificial intelligence disrupting the software sector are typical of past disruptions in financial markets.

“There are always surprises in the credit cycle,” he said, pointing to past examples of industries that appeared to be stable right before problems hit, such as newspapers, utilities and telephone companies. “And this time, it could be the software because of the AI… There are tectonic plates moving underneath, and that poses challenges to the industry.”

Mr. Dimon warned of weakness in the private credit market in October after subprime auto lender Tricolor and auto parts manufacturer First Brands filed for bankruptcy amid allegations of financial fraud. JPMorgan Chase subsequently took a $170 million impairment charge on the Tricolor loan. “When something like that happens, my antenna goes up,” he said at the time. “If you see one cockroach, there are probably more.”