Machines are starting to take the place of the people who flip burgers, drive across town and, lately, manage stock portfolios. Artificial intelligence is taking on a bigger role in making investment decisions. A.I., including an ability to analyze data and actually learn from it, is considered useful in executing certain investing models, such as high-frequency trading, and in helping fund managers with tasks that rely on gathering and interpreting reams of information. Going a step further, an exchange-traded fund introduced in October uses A.I. algorithms to choose long-term stock holdings. It is to early to say whether the E.T.F., A.I. Powered Equity, will be a trendsetter or merely a curiosity.