Cramer reveals where Goldman Sachs went terribly wrong on cruise stocks
As cruise stocks continue to roar higher this year, Jim Cramer noted that this group seemed to defy the odds of a skeptical analyst community.

In particular, Royal Caribbean , Carnival and Norwegian Cruise Line have been strong performers. Yet, in the beginning of 2017, Goldman Sachs downgraded Royal Caribbean to a sell and kept Carnival and Norwegian at neutral ratings.

"If you listen to these companies right now, instead of some of these downbeat analysts, the industry has never been better," the "Mad Money" host said.

While Cramer did acknowledge that it hasn't always been easy to own cruise stocks, he warned that investors who doubt cruise lines, do so at their own peril.

When analysts at Goldman downgraded Royal Caribbean in January, they stated that the strength of the company was fueled by cost containment efforts. It thought expectations had gotten ahead of themselves, and expected a stronger dollar and higher fuel prices to hurt earnings in the future.

Royal Caribbean also issued what sounded like a conservative outlook for 2017 in December, which didn't help the situation. Goldman stated that the stock's valuation was near the high-end of its historical range, and thought Royal Caribbean could be a laggard within the travel and leisure group, possibly aided by tax reform in Washington.

"Since then, though, business has been good and the stocks have been downright unstoppable," Cramer said.

In fact, the stocks were so strong that Goldman upgraded Royal Caribbean back to neutral and raised estimates for the entire group.

Where did Goldman go wrong? Cramer pointed to incorrect assumptions.

There has been no progress on tax reform, and the cruise industry has had strong demand. As a result, cruises have been a standout in the travel and leisure space.

After the election, analysts also predicted there would be increased inflation and a rebound in oil prices. Yet, oil still remains at low prices and inflation is minimal.

"Like many people on Wall Street, the guys at Goldman were too credulous about what politics could actually accomplish, which warped their whole worldview," Cramer said.

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