As winter starts to wrap up and we head into March, one thing is clear: Artificial intelligence (AI) investing will still be a major theme in 2025. As a result, investors need to ensure their portfolios are properly positioned to take advantage of this massive investment trend.

I have four stocks that look like top-notch buys in March. They can be divided into two categories: AI facilitators and AI hardware providers.

AI facilitators: Alphabet and Meta Platforms

Alphabet (GOOG 1.18%) (GOOGL 1.06%) and Meta Platforms (META 1.51%) are two key companies facilitating the AI arms race. Both have generative AI models to offer potential users, with Alphabet's Gemini and Meta's Llama models. How these two models are set up and utilized is entirely different, but each has a strong user base.

By facilitating the AI arms race, each is locking in a potential user base, which will pay off over the long term. Because Meta's model is free to use, it does not benefit from a subscription cost. Instead, it's using all the data it gets from being a free-to-use platform to train future models. Gemini is available as a free offering, but a premium subscription unlocks further capabilities. However, Alphabet has also woven its Gemini model into its primary business: Google Search.

AI has a huge effect on both companies, and each is heavily investing in its AI capabilities to ensure that the demand is met. Furthermore, each stock sold off substantially over the past week, as the broad tech market weakness hit both. This opens up a potential investment opportunity, as each is fairly priced, considering their growth levels.

GOOGL PE Ratio (Forward) data by YCharts. PE Ratio = price-to-earnings ratio.

At 26 times forward earnings (Meta) and 19.5 times forward earnings (Alphabet), each stock looks like a very strong buy, considering how much they benefit from the AI trend. I think each is a great buy in March, and investors should use this near-term weakness to their advantage.

AI hardware: Taiwan Semiconductor and ASML

None of these AI innovations would be possible without chip manufacturers and suppliers' equipment, which is why Taiwan Semiconductor (TSM -0.31%) and ASML (ASML 1.63%) made this list.

Taiwan Semiconductor is the world's largest contract chip manufacturer, making chips for many of the world's most advanced tech companies. It's seeing a massive boom on its AI chip side, with management expecting around a 45% compounded annual growth rate (CAGR) over the next five years for its AI-related chips. That's a massive growth rate, and it shows the high demand for hardware to power all the AI innovations.

However, Taiwan Semi has to buy machines to fulfill this capacity, which is where ASML comes in.

ASML is the only company in the world that makes extreme ultraviolet lithography machines, which lay microscopic traces on a chip. The chip technology we enjoy today wouldn't be impossible without its machines. Furthermore, ASML's technological monopoly is protected by decades of research and billions of investment dollars, so it will be almost impossible to unseat it from its leadership position.

Both ASML and Taiwan Semi are key beneficiaries of the AI arms race but also benefit from the general proliferation of chip usage. Fortunately for investors, each stock is also priced at an attractive entry point.

ASML PE Ratio (Forward) data by YCharts. PE Ratio = price-to-earnings ratio.

Both of these prices for TSMC's and ASML's stock are reasonable, considering their market leadership positions in their respective industries. These stocks look like fantastic buys in March, and investors should use any weakness to load up on them. Thanks to the AI arms race, they should be long-term market winners.