Cramer's lightning round: I prefer Union Pacific over CSX
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CSX : "CSX is good. I will tell you that my charitable trust owns Union Pacific. ... Union Pacific, I think, is a better company to own at this stage in the cycle."

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Canopy Growth : "It likes to go down. I think that's the ticket. It likes to go down. I like stocks that go higher. It seems to want to go lower. Why is that? Because the core business isn't that good. I say it's too late to sell, but do not buy anymore."

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Amyris : "They just did a big convert. People like that. No, I don't want to run from it. I think you've got to own it. Don't buy more, though. I think you own it. That's it, though."

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Rio Tinto : "I would say don't own it. It's just not worth it." Sign up now for the CNBC Investing Club to follow Jim Cramer's every move in the market. Disclosure: Cramer's charitable trust owns shares of Union Pacific.