SAN FRANCISCO (MarketWatch) -- Fewer companies' stock prices are as affected by product news as Apple Inc.'s, and the initial iPhone activation numbers from AT&T Inc. were enough to send Apple's stock down more than 6% in Tuesday trading.

Apple Inc. shares took a hit after AT&T issued what many saw as disappointing activation numbers for Apple's iPhone for the last two days of the second quarter, when the device first went on sale. In its second-quarter earnings report Tuesday morning, AT&T said it activated about 146,000 customers who bought the iPhone during those two days.

In addition, a telecommunications analyst issued a report before the opening bell that said demand for the device at retail outlets has seen a "significant decline" in recent days.

The news took some wind out of Apple's AAPL, -0.75% shares, which set a fresh all-time high of $144.18 on Friday. By the time the market closed Tuesday, Apple's stock had fallen $8.81 a share to close at $134.89.

See a video analysis of Apple's stock fall.

Anticipation over the iPhone was so intense that Apple's stock surged more than 40% since the company first announced the device at a trade show in early January. The stock has even risen 16% since June 18, when Apple announced better battery performance for the iPhone nearly two weeks before it made its debut.

The iPhone went on sale at retail outlets operated by Apple and AT&T on June 29, leaving less than two full days of sales before the end of the second quarter.

Numbers underwhelm projections

On a conference call to discuss AT&T's results, Chief Financial Officer Rick Lindner said iPhone sales expectations "were certainly high," but that demand for the device continues to be strong. "The much-anticipated iPhone launch went very well," Lindner said. "We continue to see traffic levels in our stores above historical levels."

AT&T's 146,000 activation number would not include buyers who purchased the device with the hopes to re-sell it through venues such as Craigslist and eBay. However, the figure seemed to worry investors who had been primed to expect much larger numbers. See full story.

Before Tuesday, analysts had been projecting opening-weekend sales for the iPhone of between 200,000 and 400,000 units.

A few projections reached as high as 500,000 units, with analysts citing long lines at stores and initial inventory figures for the device. Watch interview with Piper Jaffray analyst Gene Munster predicting initial iPhone sales of 500,000 units.

Andy Hargreaves, of Pacific Crest Securities, said in an interview that the AT&T report was "a reality check on what was realistic to expect" from the initial release of iPhone.

Demand was seen as strong due to months of Apple's building up anticipation for the iPhone and long lines outside of Apple and AT&T stores, in front of which some people camped out for days to ensure they would get one of the $499 or $599 devices as soon as they went on sale.

But Hargreaves said the AT&T numbers "still have a little bit of confusion in them," and may not completely give a full picture of how iPhone sales did over that first weekend.

Many consumers said they were buying iPhones in order to re-sell them, which wouldn't be reflected in AT&T's activation numbers, and Hargreaves reiterated that there were barely one-and-a-half days of iPhone sales to be included in the quarterly results. Hargreaves holds an outperform rating on Apple's stock.

"It still doesn't change my perception of the launch of the iPhone," said Hargreaves, who anticipates Apple will report iPhone sales of above 200,000 units and give a fuller picture of its results when the company delivers its third-quarter earnings report on Wednesday. See full story.

Analyst notes 'thin demand'

"We have noticed decent inventories [of the iPhone] at stores, and thin demand at best," analyst Ittai Kidron of CIBC World Markets wrote in a report Tuesday. "In fact, most Apple store visitors were not looking at the device and only a very small subset bought it."

Kidron based his findings on "store checks." He also noted a recent survey of buyers of the device found that its key drawback is "poor data connectivity" that affects how quickly users can access and use the Internet over the device.

The iPhone works over AT&T's T, -0.28% EDGE network for data, which is slower than other so-called 3G networks that are coming online in markets around the world.

Because of his findings, Kidron expects Apple to release a 3G version of the iPhone before this year's holiday season. Apple has given no indications of when or if it will update the device.

"With the weakness, we wouldn't be surprised to see AT&T and Apple step up their marketing efforts," he wrote.

In addition to the iPhone numbers from AT&T, the iPhone was clouded by reports that it could be hacked into in Wi-Fi hotspots or at some Web sites, due to security glitches in the device.