Artificial intelligence (AI) stocks were on fire in 2025.  During the year, there was an explosion of demand for cloud computing and automation. At the same time, there was a small pool of AI stocks listed on the ASX which meant investors had limited choices for where to put their money. As a result, ASX AI stocks saw their share prices skyrocket. As we move in 2026, it looks like investment and adoption of AI-driven technologies is here to stay.  And if 2026 is anything like the past year, there is one unstoppable ASX AI stock you'll want in your portfolio. The artificial intelligence stocks I'd keep in my portfolio Over in the US, Nvidia Corp (NASDAQ: NVDA) is widely considered to be the top AI stock to own into 2026 due to the company's dominance in the AI processor and infrastructure space.   But looking closer to home, NextDC Ltd (ASX: NXT) shares present an excellent opportunity for Australian investors to jump aboard the AI-train before the next boom. The data centre operator's shares closed in the red on Monday afternoon. At the time of writing the shares are down 1.91% to $12.30 a piece. For 2026 so far, the shares are 2.15% lower. Over the past year, the shares have dropped 18.54%.  While it might not be the best start for NextDC shares, the AI stock is primed to soar over the next 12 months. Here's why. NextDC operates a rapidly expanding network of data centres focused on cloud computing, telecommunication networks and supports AI workloads. It has physical centres, cooling, power, and security services and project support. As data usage explodes, demand for secure, high-quality infrastructure is likely to grow alongside it. The company is heavily investing in expanding its business too. The company recently announced it has partnered with OpenAI to develop and operate a hyperscale AI campus and large-scale GPU supercluster at its site in Sydney. It'll be the largest data centre in the southern hemisphere.  Just two weeks following the announcement, NextDC announced that its pro forma contracted utilisation increased by 96MW or 30% to 412MW since its last update on 1 December. As AI workloads increase, NextDC is positioning itself well to absorb a lot of the demand. What's next for NextDc shares? I'm very optimistic that 2026 will be the year for growth of NextDC shares.  TradingView data shows analysts are equally bullish. All 13 analysts have a buy or strong buy rating on the shares with an average target price of $21.04. At the time of writing this implies the shares could jump 71.04% higher over the next 12 months.  However, some think the increase could be even higher. The maximum analyst target price is $29.36, which implies an incredible potential upside of 138.70% in 2026!