Cramer's Homework: Two Stocks Up More than 100% YTD

(Click for video linked to a searchable transcript of this Mad Money segment)

Sometimes Jim Cramer tells a caller that he needs to do homework before he can make a decision on a stock. And he's not kidding.

Following is Cramer's research or homework on stocks recently called to his attention by investors who watch the TV show.

USANA Health Services (USNA)

On June 7th, Mario in California called in about USANA Health Services, a multi-level marketing company focused on nutritional supplements, weight management and personal care products.

Shares have surged over the past 6 months; on June 14th they were almost 125% higher ytd.

If you're long, it probably comes as no surprise that Cramer suggests taking profits.

However, Cramer's caution stems from more than the sharp gains in share price. "The company is undergoing a reorganization of its management team," he said and the Mad Money host is always cautious when big changes happen at the top.

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"The CFO stepped down and the Chief Operating Officer resigned six months ago.," Cramer said. That's never good

"If you own USANA, take a victory lap and ring the register. If you don't own it, I think this stock is too risky and I suggest you stay away. USANA is looking like a battleground stock, and I don't want you to step into the crossfire."

Tooga | Getty Images

Clovis Oncology (CLVS)

Also on June 7th, Virginia who lives in Virginia asked about Clovis Oncology, a company that specializes in cancer treatments.

The advance in Clovis has been nothing short of spectacular; shares are more than 300% higher ytd.

Cramer believes the pop reflects Street enthusiasm for two of its drugs with new information presented earlier in the month at the American Society of Clinical Oncology (ASCO) annual meeting.

"The data was very impressive and suggests there's potential for further gains," Cramer said.

Nonetheless, the Mad Money host can't dismiss the incredible 300% surge. "I think the story has legs but after a spike like that, I don't want to chase. Wait for a pullback," he said. "After such an epic move, you have to be careful, especially since the smoking hot cancer drugs that caused the rally are still only in phase one development."

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