Tim Cook steps down as Apple CEO, passing leadership at a pivotal moment. The company just posted record sales, but faces serious supply-chain threats from RAMageddon, a RAM shortage that could crimp revenue growth.

Cook warned investors that the memory chip shortage will create headwinds for Apple's business in coming quarters. The timing cuts both ways. Apple's record sales demonstrate the strength of its brand and ecosystem, but the incoming supply constraints mean the next leader inherits a company vulnerable to component shortages outside its control.

The RAM shortage stems from overproduction and inventory corrections across the semiconductor industry. It directly threatens device manufacturers relying on consistent memory supply. For Apple, historically insulated from such pressures through scale and supply-chain dominance, the warning signals a shift. The company cannot simply order its way around the problem.

Cook's departure arrives as Apple navigates this headwind, placing the incoming CEO in a position to either mitigate supply risks or absorb margin pressure. The record sales soften the blow, but investors now watch whether Apple's legendary operational execution extends to managing chip shortages.