Berkshire Hathaway, which Buffett is the chairman of, has increased its Apple stake, "[So], he obviously does not care about the so-called supercycle of the [iPhone] X not working well," said Cramer, whose charitable trust owns shares of the tech giant.
Earlier this month, Apple reported the number of iPhone units sold in the first quarter fell from a year earlier, despite expectations for modest growth.
"Warren Buffett does not flee with the wind or fly with the wind. He makes judgments," Cramer said on "Squawk on the Street."
A quarterly filing released Wednesday showed Berkshire increased its holdings of Apple by 23.3 percent to 165.3 million shares, sending shares of the iPhone maker climbing more than 2 percent on Thursday.
Berkshire first made an investment in Apple in 2016 after a person at the firm bought about 10 million shares. Buffett then looked at the stock and purchased considerably more, the billionaire recalled in August to CNBC. He added he's never sold an Apple share.
Cramer also spoke about a note by Morgan Stanley's Katy Huberty, which showed the iPhone X winning market share in China during the fourth quarter of 2017.
"She's been right," the host of CNBC's "Mad Money" said about Huberty.