Apple Watch
Apple CEO Tim Cook speaks about the Apple Watch. Reuters

Apple’s biggest product unveiling in the post-Steve Jobs era disappointed more than impressed investors on Tuesday. Shares rose about 4.5 percent after the company announced a new mobile payment system but then dropped 6 percent in the hour after CEO Tim Cook introduced the long-anticipated Apple Watch, which Cook called “the most personal device we’ve ever created,” at the event in Cupertino, California. In the next hour, shares fell another 1.4 percent, and in the first few minutes of after-hours trading, Apple shares fell another 0.5 percent to $97.85, more than a dollar less per share than at the opening bell.

Before the announcement, Wall Street had boosted Apple Inc. (NASDAQ:AAPL). That pre-unveiling stock rise has become so predictable, there's a standard line for it: Investors buy the rumor and sell the news.

Apple's first wearable tech product is a computer bracelet that offers wearers real-time health indicators, a navigation system, messaging, home management, online shopping and more.

The device has long been expected by techies and Apple fans, though wearable tech has been around for decades, starting with calculator watches in the 1980s. This year, nearly every major tech company has released a smartwatch, including Google (NASDAQ:GOOGL), Sony Corp. (NYSE:SNE), Samsung Electronics Co. (NASDAQ:SSNLF) and Motorola Solutions Inc. (NYSE:MSI).

Shares of Samsung, Apple's chief competitor, remained unchanged Tuesday at $1,175.

Apple also announced it plans to launch a mobile payment system called Apple Pay in October. The system would enable those with the latest iPhones (6 and 6 Plus) to place their smartphone next to a sensor to pay in participating stores or through apps such as Target, Uber and Groupon, without storing credit card numbers on the phone.