This chart shows how AI hype has taken over the stock market as companies try to cash in on the frenzy

Two-thirds of companies that mentioned AI on earnings calls saw their stocks rally, according to a study from Wall Street Zen.

• Companies that mentioned AI in earnings saw their stocks rise 4.6% on average, a study from Wall Street Zen found.
• Meanwhile, companies that didn't mention AI saw stock gains of nearly half that.
• The chart above shows how the number of AI mentions has ballooned to an all-time high.

Artificial intelligence has gripped the attention of Wall Street over the last year.

ChatGPT stormed onto the scene last November, quickly becoming a viral web tool, and companies across sectors have taken notice.

A new analysis by Wall Street Zen found the number of mentions of "AI" and related terms (machine learning, automation, robots, etc.) in S&P 500 earnings calls skyrocketed over the past year and a half, as the chart above illustrates. 

AI mentions in the first quarter of 2022 totaled 1,156. That dipped to 805 in the third quarter of 2022 before rising 177% to 2,182 in the next quarter.

Then, during this year's second quarter, that ballooned to 7,358 — a 366% increase compared to the start of the year.

The Wall Street Zen study also found that companies that said AI during earnings calls saw an average stock price increase of 4.6% in the three days afterwards — nearly double the 2.4% gain seen by companies that did not mention it. 

What's more, 67% of companies' stocks climbed after mentioning AI, and among those gainers the jump was 8.5% on average. 

"Time will tell if the AI boom is a bubble," the researchers wrote. 

Among the companies that saw the largest stock price gains in the three days following a mention of AI, Adobe led the way with a 38.2% increase.

Carrier Global, Meta Platforms, Match Group, and Expedia followed, with gains of 38.1%, 37.6%, 37.5%, and 35.4%, respectively.

Nvidia, one of the hottest stocks of the year, saw its share price jump 26.3%, though shares also soared leading up to earnings reports on expectations that it's a top beneficiary of the AI wave.

Still, veteran investor Rob Arnott on Tuesday called the chipmaker is a "textbook story of a Big Market Delusion."

"Overconfident markets paradoxically transform brilliant future business prospects into even more brilliant current stock price levels," he wrote in a note. "Nvidia is today's exemplar of that genre: a great company priced beyond perfection."