Amazon's (AMZN -1.27%) shares have skyrocketed well over 40% in 2023. Yet, it's still nowhere close to being the top-performing mega-cap stock this year. Meta Platforms and Nvidia are duking it out for that honor.

All the huge high-flying stocks have one key thing in common: They're focused on artificial intelligence (AI). And they all should have tremendous opportunities ahead. It's a tough call to identify which will be the biggest winner of the group. However, here's why Amazon just might be the best AI stock to buy right now.

Olympus on the horizon

OpenAI's GPT-4 is widely viewed as the best large language model (LLM) available today. It reportedly has 1.76 trillion parameters. With AI systems, parameters are the variables used to transform input data into output data. Generally speaking, the more parameters an LLM has, the more powerful it is (although higher numbers don't always translate to better performance).

Amazon launched its own LLM, called Titan, earlier this year. Granted, Titan isn't at the same level as GPT-4. But Amazon continues to move forward aggressively with its AI development.

Reuters recently reported that the company is investing heavily in training a new LLM. According to Reuters ' sources, this new AI model, code-named "Olympus," has roughly 2 trillion parameters. While the parameter count doesn't automatically mean Olympus will outperform GPT-4, it's probably a good bet that it will, at minimum, be very competitive with its rival from OpenAI.

Amazon's key advantage

Of course, OpenAI isn't resting on its laurels. CEO Sam Altman confirmed this month that his company is actively working on GPT-5. Alphabet's Google is also rumored to be developing a much more powerful AI model called Gemini.

But Amazon could have a key advantage over its competition, one that CEO Andy Jassy alluded to in the company's third-quarter earnings call. Jassy said, "Customers want to bring the models to their data, not the other way around. And much of that data resides in AWS [Amazon Web Services] as the clear market segment leader in cloud infrastructure."

AWS's strategy is to offer multiple LLMs as a service through its Amazon Bedrock platform. Several third-party providers, including AI21, Anthropic, Cohere, and Stability AI, offer access to their LLMs on Bedrock. Meta's Llama 2 and Amazon's own Titan LLM are also available. The addition of Olympus, though, could make AWS much more attractive to customers.

Amazon will likely also leverage Olympus in other ways. For example, the company could make its CodeWhisperer generative AI coding companion more powerful. Jassy noted in the Q3 call that all of Amazon's "significant businesses are working on generative AI applications to transform their customer experiences." Olympus could make those initiatives even more transformative.

Beyond AI

There are other reasons Amazon could be the best AI stock to buy right now, though. And they don't all directly relate to AI.

Importantly, Amazon continues to expand into new markets. Jassy announced on Thursday that the company will begin selling cars online in the U.S. in 2024. Hyundai will be the first brand offered, but others could follow. Amazon launched another new service -- Supply Chain by Amazon -- in September. The company is leveraging its own massive supply chain network to help external customers.

Also, Amazon's profits more than tripled year over year in Q3. The company's streamlining efforts are definitely paying off. Sure, Nvidia's earnings growth in its latest quarter was even more impressive. However, it remains to be seen how sustainable the chipmaker's trajectory will be as the supply-demand imbalance for its graphics processing units (GPUs) is resolved.

The best is yet to come

You might have noticed I've used some waffle words. Amazon might be the best AI stock. Amazon could be the best AI stock. The reality is that I don't know for sure which AI stock will emerge as the biggest winner in the long run. No one does.

What I do feel confident stating, however, is that Amazon will profit tremendously from the AI boom. Even if it doesn't turn out to be the best AI stock, I believe the best is yet to come for the e-commerce and cloud services giant.