Jim Cramer says some analysts don't seem to believe in the Trump rally, and are fighting it tooth and nail — especially when it comes to Apple.

"At the end of the day, there is a big difference between expensive stocks, and stocks that have run. These analysts don't seem to understand that distinction, but I think they are making a big mistake," the "Mad Money" host said.

Oppenheimer reiterated a buy rating on Apple on Monday, but said it expects iPhone sales to peak in fiscal year 2018, writing that "we believe Apple lacks the courage to lead the next generation of innovation; instead it will become more reliant than ever on the iPhone."

Ultimately, Opco said it expects Apple to "embark on a decade long malaise. The risks to the company have never been greater."

Cramer was flabbergasted.

Aside from the fact that Apple could add as much as $40 per share if the government allows its massive overseas cash hoard to repatriate to the U.S. under President-elect Donald Trump, its stock is also insanely cheap at just 10 times 2018 earnings projections.

Cramer was also willing to bet that the company's service stream, with more than 1 billion users, could be gigantic.

The downbeat analyst projections affected more than just Apple, too. Last week, there were many downgrades of bank stocks, which have roared since Trump's surprise victory. Regional banks and major banks have been downgraded, as analysts say they have been overvalued and are ahead of themselves.

"Despite their monster moves, the banks stocks are so far behind the rest of the market it is almost laughable," Cramer said.

Cramer failed to see how banks could be ahead of themselves when they are nowhere near where they used to be, especially with the expectation that Trump will ease regulation, there will be rate hikes. The group is a buy, not a sell, Cramer said.

Goldman Sachs also downgraded Caterpillar to a sell from a hold because of "extended commodity infrastructure downturn" back in January, and provided a price target of $51. Caterpillar closed at $92 on Monday.

"I don't want to fight that tide of potential good news for Apple or for any of these stocks," Cramer said.

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