Apple Inc.’s credit risk is “inconsistent” with the double-A rating category awarded to the iPhone maker by Moody’s Investors Service and Standard & Poor’s, according to Fitch Ratings.

While Fitch hasn’t released a public grade for Apple, “inherent business risk that overshadows a significant liquidity cushion” means such a ranking would likely fall “at the highest end” of the single-A tier, Fitch analysts led by James Rizzo wrote today in a report. That’s at least three levels lower than the Aa1 rating from Moody’s and equivalent AA+ grade from S&P.

Apple, which is preparing to sell debt to help finance a $100 billion capital reward for shareholders, had $145 billion of cash on March 30, more than the combined funds of every triple-A rated U.S. company, according to data compiled by Bloomberg. That balance sheet strength is eclipsed by the risk from volatile consumer preferences, significant competition and rapid technology changes, Fitch said.

“Consumer product companies such as Sony, Nokia, and Motorola Mobility have proven the risks related to ever-changing consumer tastes, low switching costs, and a highly competitive environment,” Fitch analysts wrote in the report. “Each has historically had a dominant market position and strong financial metrics, only to falter over a relatively short period of time.”

Concern that Apple’s pace of sales growth is slowing was reinforced last week by a forecast that revenue this quarter may miss analysts’ predictions by as much as $4.9 billion. Apple had its first profit decline in a decade last quarter amid accelerating competition in mobile devices from Samsung Electronics Co.