On Monday's CNBC "Stop Trading" segment, TheStreet's Jim Cramer looked at two "powerhouse downgrades."

The first of which was Monster Beverage  (MNST - Get Report) , which was downgraded to hold from buy by Bonnie Herzog of Wells Fargo, one of Cramer's favorite analysts. This stock has been doing well but Herzog says the second quarter could be soft for its U.S. business, explained Cramer, the co-manager of the Action Alerts PLUS portfolio.

Previously, Monster's problem was Europe. But Coca-Cola's (KO - Get Report) investment in the company allowed Monster to use Coca-Cola's distribution network to boost its results. 

"Be careful, though," Cramer said on Monster, "Herzog is very, very strong." Shares are down more than 4% in response to the downgrade.

Cramer also looked at Stratasys (SSYS - Get Report) and 3D Systems (DDD - Get Report) , which are down 10% and 8%, respectively, after being downgraded by analysts at Piper Jaffray. 

The analysts downgraded these stocks because of the 3-D printing capabilities that HP Inc. (HPQ - Get Report) is now producing. While Cramer had been critical of HP Inc. in the past, he acknowledged that its 3-D printing machines are "remarkable," particularly for corporate use, and the company has done a great job in this area.

That's bad news for Stratasys and 3D Systems.

At the time of publication, Cramer's Action Alerts PLUS had no position in companies mentioned.