Warren Buffett is the CEO of Berkshire Hathaway ( BRK.A 0.99%) ( BRK.B 0.95%), which has delivered an annual return of 19.8% since Buffett took the helm in 1965. That could have turned an investment of $1,000 into more than $42 million. The same investment in the S&P 500 index would have grown to just $308,115 over the same period.

The storied investor tends to “zig when everybody else zags,” a top analyst said.

The stock market has been hitting new highs this year as excitement continues to build with respect to artificial intelligence (AI) and the opportunities that may open up for many businesses. Should investors take Buffett's conservatism in the markets this year as a red flag?

Investors hoping to benefit from the AI boom are focused on technology companies. That is especially true of Palantir and Nvidia, the second- and third-best performing stocks in the S&P 500 this year, respectively. But Vistra is currently the best performing member of the index, and it hails from the overlooked utilities sector.