If you didn't manage to nab an iPhone X shortly after pre-ordering began Friday, you might have to wait until mid-December to get your hands on Apple's 10th-anniversary phone, as pre-order supplies reportedly sold out quickly.

While manufacturing and supply issues, along with the device's $1,000 price tag, had been raising concerns that the iPhone X (pictured above) might not sell as well as previous releases, Apple said in a statement Friday that pre-ordering demand was "off the charts."

Those early indicators of strong demand have prompted some analysts to revise their forecasts for iPhone X sales upward. Those indicators also briefly pushed Apple stocks to a new high today, with company shares continuing to perform strongly as of this morning.

Forecast: 'Super Cycle' of Upgrades

Officially set to be released Friday, the iPhone X could see pre-order sales of as much as 50 million units, compared to previous expectations of 40 million, according to an upgraded forecast released today by the analyst firm GBH Insights. In a research note, Daniel Ives, the firm's chief strategy officer, said that he expects the device to be a "stellar success."

"In a nutshell, we believe iPhone X demand will be strong in the US and especially China as overall our survey feedback indicates that 40% to 45% of iPhone upgrades in FY18 will be iPhone X devices with iPhone 8/8+ tailwinds helping set up a 'super cycle' upgrade over the next year," Ives aid in an earlier note this month. "While supply chain issues will elongate the iPhone X upgrade cycle well into FY18, we believe seeing the 'forest through the trees' will translate into this super cycle upgrade being a major growth catalyst for Apple (and its investors) over the coming year."

Nomura Instinet is also predicting a strong performance for the iPhone X, although another equity research analyst firm, Drexel Hamilton, cautioned that supply constraints could be another reason pre-order customers are seeing shipment delays of five to six weeks.

However, KGI Securities analyst Ming-Chi Kuo said in a research note that any supply problems that Apple has experienced with iPhone X components, such as the camera's facial recognition technology, are likely to stabilize with subsequent releases from Apple.

Questions about iPhone 8

Although the iPhone X devices will begin making their way into at least some owners' hands this week, Apple puts tight controls on what consumers are able to see until it's ready to release details.

That's why one Apple engineer reportedly lost his job recently. According to a YouTube video posted over the weekend by his daughter, the engineer was fired after she video recorded images of a pre-release iPhone X during a visit with her dad to the company's cafeteria. Taking photographs and filming is prohibited on Apple properties.

Meanwhile, the latest developments with the iPhone X could raise questions about how well Apple's other new phones, the iPhone 8 and iPhone 8 Plus, might perform. Some reports have already described sales of those devices as weak, with many observers saying they believed buyers were holding off until the iPhone X came out.