Shares of Apple (AAPL -1.32%) popped on Tuesday, rising to more than $207. The move higher follows the company's annual Worldwide Developers Conference, where the iPhone-maker said it will start rolling out its beta artificial intelligence (AI) software, called Apple Intelligence, this fall. Investors applauded the company's move into AI, sending shares up more than 7%.

The stock's sharp gain on Wednesday puts it up about 21% over the last three months. With such a steep gain in the rearview mirror, many investors are likely taking a close look at the tech stock to see whether it's a buy, sell, or hold.

So, do shares remain attractive today, even after soaring?

Apple's big move in AI

"We've been using machine learning and artificial intelligence for years," said Apple CEO Tim Cook during a Tuesday keynote. Until now, computing power wasn't yet sufficient to enable the company's vision for AI across its devices, Cook explained. Hence Apple's announcement that it is bringing to market AI software called Apple Intelligence -- an AI Cook says is "powerful," "intuitive," "integrated," "personal," and "private."

"It's the next big step for Apple," Cook proclaimed. Given the stock's more than 7% gain on Tuesday, many investors seem convinced the software update can fuel strong growth for the company.

Perhaps one of the big reasons why investors are bullish on the stock's potential following the announcement of Apple Intelligence is that the AI software will only be available on recent Apple products. As far as its smartphones go, for instance, Apple Intelligence is limited to the iPhone 15 Pro and Pro Max (note it's not even available on the standard iPhone 15). This could lead to a big wave of smartphone upgrades from Apple's loyal customer base as consumers look to get their hands on more AI tools.

Apple Intelligence is also limited to newer Macs and iPads. It will be available on iPad and Mac devices with M1 chips and later.

The iPhone, accounting for over half of Apple's annual revenue and an even larger portion of its profit, can move the needle on the company's bottom line in a big way when the product segment's sales accelerate. Analysts seem to agree with this sentiment. In response to the event, many prominent Wall Street analysts released notes to investors saying that iPhone sales may accelerate -- particularly when the company announces its latest iPhone this fall.

But what about the stock's valuation?

Some investors, however, might argue that a potential acceleration in iPhone sales later this year was already priced into the stock. After all, shares were trading above 30 times earnings ahead of the announcement of Apple Intelligence. A premium like this prices in meaningful and sustainable bottom-line growth for years. Even more, the media was largely predicting some sort of new AI feature from Apple before the company's keynote this week.

So, is Apple stock a buy, sell, or hold after the stock's big gain? Given that Apple has benefited from big waves of iPhone upgrades before, it's definitely possible Apple Intelligence will bolster iPhone sales trends. For this reason, selling Apple shares at a time like this could be a mistake. But buying shares at this level, unfortunately, leaves very little margin of safety for the upbeat expectations priced into the stock. For this reason, it's probably more appropriate to call Apple stock a hold at this level. Investors, of course, should do their own due diligence to decide for themselves how attractive they think shares are.