Gloomy economic news and the wild swings of the stock market may be getting you down. But at least you can count on this: We’ve entered the sweet spot of the iPhone cycle.

Since Sept. 19, when the iPhone 6 and its larger sibling, the iPhone 6 Plus, went on sale, consumers have been ordering the gadgets faster than Apple can deliver them. The ripple effects are being felt throughout the economy — and they have been moving the stock market.

“The iPhone is having a measurable impact,” said Michael Feroli, the chief United States economist for JPMorgan Chase. “It’s a little gadget, but it costs a lot and it seems that everybody has one. When you do the multiplication, it’s going to matter.” He estimates that iPhone sales are adding one-quarter to one-third of a percentage point to the annualized growth rate of the gross domestic product.

You may not think of the iPhone as a financial powerhouse. After all, it’s just a consumer good — albeit a highly functional, high-end one that you can carry in your pocket or your purse. Sales typically surge every two years when, as now, Apple does a major iPhone upgrade. You may have the warm and personal relationship with the iPhone that Timothy D. Cook, Apple’s chief executive, described on Monday to Wall Street analysts during a conference call. Apple’s next three months will be “incredibly strong,” he said. And he spoke enthusiastically about the principal reason for this performance: “These iPhones are the best we have ever created and customers absolutely love them.”