Wall Street's AI heavyweights added a combined half a trillion dollars in stock market value late on Wednesday after quarterly reports from Microsoft and Meta Platforms showed massive investments in the emerging technology were paying off.

Meta Platforms also reported earnings after Wednesday’s close. Coming into the earnings, the option market had priced the straddle at 42 points, or 6% of the stock price. That straddle price was cheaper than six of the past 10 post-earnings moves by Meta — meaning that the odds were theoretically slightly in favor of buying the straddle.