Shares of Apple rose only 2 percent to $416.59, in the first half hour of Friday trading, two hours after the iPhone 4S was first handed out to customers in the Eastern time zone.
Apple had announced Wednesday that it had sold out of the first batch of iPhone4S models, distributed for the first time by Sprint-Nextel, as well as original iPhone carrier AT&T and the more recently added Verizon Communications. Apple's 310 retail stores are also selling the new product.
Long lines of customers were reported at mobile stores in the Eastern U.S., where some had started to line up early Friday. Analysts predict the company may sell as many as 4.4 million iPhones 4s units by Monday.
The initial gain in shares of the Cupertino, Calif.-based Apple boosted its market capitalization to $385.8 billion, maintaining its status as the world's most-valuable public company. Exxon Mobil, the No. 2, was valued around $376.5 billion in early Friday trading.
Apple shares have risen 29.6 percent in 2011.