Buyer beware on Advanced Micro Devices (AMD) - Get Advanced Micro Devices, Inc. Report shares at these new euphoric levels. 

Shares of the chip-maker have skyrocketed 25% in August on optimism the company's chips would wrestle more market share away from struggling rival Intel (INTC) - Get Intel Corporation (INTC) Report . AMD's stock has surged about 121% this year, bringing the company's market cap to a lofty $24 billion.

The company unveiled its new Radeon server card Monday that is designed specifically for data-center virtualization. That led to another 5% pop on the session.

Intel shares have gained slightly on the year. AMD has also out-performed chip darling Nvidia's (NVDA) - Get NVIDIA Corporation Report 28% year to date advance.

AMD's CEO Lisa Su offered up a bullish outlook on the business in a post-second quarter earnings interview with TheStreet. Most on Wall Street share her assessment.

TheStreet Recommends

"AMD is executing well on its product roadmaps, in our view, which is resulting in market share gains, solid top line growth, margin expansion and a lower net leverage ratio that could reach two times exiting this year (down from 2.5 times net leverage exiting the second quarter)," says JPMorgan analyst Harlan Sur.

But not all are crazy upbeat. In fact, some are sounding the alarm bell.

Miller Tabak strategist Matt Maley points out when AMD's relative strength index (RSI), a key technical measure, breaks above 80 as it has currently a sharp pullback ensues.

"That's a higher level (RSI of 84 on Aug. 24 closing basis) than it stood back at the 2000 highs, and almost all of the times the weekly RSI has moved above 80 in the last 20 years has been followed by a meaningful pull-back in the stock," Maley says.

Maley adds, "In other words, it had all the signs of a buying climax....and thus investors might want to be a little careful with AMD at these levels right now."

Here's why Jim Cramer is bullish on AMD rival Nvidia.