Bill Ackman of Pershing Square Capital Management and Andreas Halvorsen of Viking Global Investors are two billionaires worth following for investment ideas. They are entrusted with billions in assets to manage for clients, and that reflects a career of making smart investment choices.

At the moment, artificial intelligence (AI) looks like it will continue to be a dominant theme across the market in 2025, so you might want to start by looking at companies that compete in that arena.

The rapid growth of the artificial intelligence (AI) market drove many stocks to record highs over the past few years. That's why shares of Nvidia, the chipmaking bellwether of that booming market, surged 2,