These stocks are riskier than your household names, but pack portfolio-changing potential if they work out.If you want to invest in artificial intelligence (AI), there are plenty of companies to choose from. Household names like Microsoft or Nvidia come to mind.However, keep in mind that these companies are worth trillions of dollars today. There is a good chance that their best returns are in the rearview mirror. You'll need to venture into the unknown if you're hunting for life-changing investment returns ...