Visa and Mastercard scored record highs Wednesday after a massive charge up this year. Buyer beware, said one market watcher.

“I’m a little cautious here. They’re getting very overbought,” Matt Maley, equity strategist at Miller Tabak, told CNBC’s “Trading Nation” on Wednesday.

A 24 percent year-to-date rally and four straight months of gains has placed Visa as the second-best performing stock in the Dow in 2018.

Maley has worries over its technicals, however. Its monthly relative strength index has not dipped below 80 this year. An RSI, which measures overbought or oversold conditions, is typically considered overbought when a measurement reads above 70.

Mastercard is even worse, said Maley.

“On Mastercard, it’s above 90. In fact, it’s above 92. That’s the highest it’s ever been so it’s the most overbought it’s ever been,” he said.

Mastercard’s monthly RSI exceeded 95 in July. Its shares are up 41 percent in the year to date, putting it on track for its eighth straight year in the green.

“That doesn’t mean these aren’t good companies, that they don’t have good fundamentals, but they’ve had a big run,” added Maley. “They could go a little bit higher from here, but I’d want to buy them on weakness rather than chase them way up here.”

No matter the cost, Boris Schlossberg, managing director of BK Asset Management, is a devotee of both stocks.

“This is the type of trade I would just buy. If it comes in, I’d buy even more because I think long term these are some of the best stocks that we have in the digital universe,” Schlossberg said on Wednesday’s “Trading Nation.”

Schlossberg says both companies’ strong fundamentals make up for any kind of nerves over their steep rallies.

“They have unbelievable business models. As a matter of fact, I think they’re sort of the real bitcoin, save for the anonymity, because they are the true digital cash of our present,” said Schlossberg. “Their moat is so huge at this point.”

Visa beat earnings and sales estimates in its release after the bell Wednesday. Mastercard is set for Thursday morning.