Last year, PwC estimated that the productivity gains from artificial intelligence (AI) would add $15.7trn to the global economy by 2030. Given this potential, it’s understandable that many investors want AI exposure in their ISA portfolios.

Here are three AI-related stocks that I’d consider buying with spare cash sitting in an ISA.

Picks and shovels play

First, we have Taiwan Semiconductor Manufacturing Company (NYSE: TSM). The share price is up 258% over the past five years, but down 18% since July.

TSMC, as it’s known, makes most of the advanced chips needed for AI hardware, particularly for data centres and GPUs used by companies like Nvidia and Advanced Micro Devices.

As AI applications grow, demand for more powerful and efficient chips increases, directly benefitting TSMC. Its expertise in cutting-edge manufacturing (3nm chips, for example) makes it a key enabler of AI progress.

In Q2, revenue surged 32.8% year on year to $20.8bn, while earnings also grew by over 30%. The firm reckons it can grow revenue at a compound annual rate of 15%-20% for the next “several years“.

Political risk is unavoidable here due to the company being based in Taiwan. China’s official policy is to one day reunify the island with the mainland. So this needs considering.

However, the stock’s forward-looking price-to-earnings (P/E ratio) is around 20. For a growing firm that sports a 38% profit margin, that strikes me as good value.

AI infrastructure

Next up is Amazon (NASDAQ: AMZN). The tech giant is a major AI power due to its AWS (Amazon Web Services) cloud platform, which offers AI development tools to millions of customers worldwide.

On 5 September, it was announced that Central Japan Railway Company had partnered with AWS. The firm, which operates the world’s fastest trains, will use AWS generative AI and machine learning to improve track maintenance and passenger experiences.

In Q2, sales at AWS rose by 19% to $26.2bn, its fourth straight quarter of accelerating year-on-year growth. It signed new agreements with a multitude of global customers.

AWS does face competition from Google Cloud and Microsoft Azure. So Amazon will need to keep investing and innovating relentlessly to stay at the top of the cloud infrastructure market.

A ready-made portfolio

Finally, if I didn’t want to pick individual stocks, I’d go for Polar Capital Technology Trust (LSE: PCT).

This is an investment trust from the UK’s FTSE 250 index that has all the big AI players in its portfolio. So we’re talking Microsoft, Alphabet and Meta Platforms, as well as TSMC and Nvidia.

Microsoft has a big stake in OpenAI, the maker of ChatGPT. Alphabet is the parent of Google, which some estimates say processes around 20m terabytes of data per day across search, YouTube, and Gmail.

The trust’s share price is up around 92% in five years. But one risk here would be a worsening in the tech sell-off we’ve seen recently. Its top holding is Nvidia, which has borne the brunt of the selling so far (down 24% since mid-June). Investor sentiment could further sour.

Long term, however, the trust looks perfectly placed to benefit from the unstoppable digitalisation of the world. Even better, it’s currently trading a 11.6% discount to the value of its underlying assets per share.