A new bull market for the Nasdaq Composite Index has been in sight for several months. The wait is over. In May, the index finally gained more than 20% from its previous bottom, meeting the commonly accepted definition of a bull market.

There have been plenty of winners, with over one-third of the Nasdaq 100 stocks jumping by at least 20% so far this year. Some of them should have even more room to run. Here are three high-flying stocks to buy now.

1. Alphabet

Shares of Google parent Alphabet (GOOG 1.25%) (GOOGL 1.27%) have soared close to 40% year to date. The primary catalyst behind this impressive gain can be summed up in two words: artificial intelligence (AI).

After OpenAI's ChatGPT generative AI chatbot practically became an overnight sensation, some worried that Alphabet could be left behind. Those concerns were premature. The tech giant roared back by rolling out multiple new AI products of its own.

What about predictions that AI could still present a big threat to Google? Even with the rapid rise of ChatGPT, Google Search hasn't lost any market share. Alphabet is also embedding generative AI into Google Search and using the technology to make it easier to create ads -- moves that could attract additional advertisers.

Google Cloud should be a big winner as organizations scramble to build their own AI apps. The unit offers tools that streamline AI development. Don't be surprised if Google Cloud gains additional market share more quickly than its rivals over the next decade.

2. Amazon

AI has fueled Amazon's (AMZN 1.30%) rise in 2023 as well. The e-commerce and cloud services stock has skyrocketed more than 45% year to date.

Amazon Web Services (AWS) continues to reign as the biggest player in the cloud market. The same dynamics serving as a major tailwind for Google Cloud are working to AWS' advantage also.

But Amazon is putting AI to work in another important way. The company's supply chain uses AI extensively. And it gives Amazon a significant competitive advantage. Shopify's recent decision to sell most of its logistics business underscored this point.

Look for Amazon's profits and free cash flow to improve over the next few years. The company has shuttered underperforming businesses, downsized staff, and reprioritized capital spending. When these efforts begin to show up in a major way on Amazon's financial metrics, investors' interest in this stock could intensify.

3. Microsoft

Microsoft (MSFT 1.65%) has been at the forefront of the AI boom of recent months. The company invested billions of additional dollars in OpenAI and integrated ChatGPT throughout its product line.

These moves paid off big-time for shareholders. Microsoft stock has jumped nearly 40% this year. That's not an easy feat for a company that was already the second-largest trading on a U.S. stock exchange based on market cap.

Like AWS and Google Cloud, Microsoft's Azure cloud unit has a massive growth opportunity with AI. Many of the company's other products should benefit as well, including its Bing search engine and Office productivity apps.

Microsoft is also well positioned to become a bigger force in the gaming market. The company already markets the popular Xbox gaming system. It recently cleared a key hurdle by winning EU approval to acquire Activision Blizzard. Now Microsoft only needs to secure green lights in the U.S. and the U.K. to finalize the deal.