Apple’s revenue during its fiscal fourth quarter was up 29 percent as each of its product lines posted increases. The gains, however, could have been much larger, according to Apple CEO Tim Cook. “We had a very strong performance despite larger than expected supply constraints, which we estimate to be around $6 billion,” he said. “The supply constraints were driven by the industry wide chip shortages that have been talked about a lot, and COVID-related manufacturing disruptions in Southeast Asia.”