-+ 0.00%
-+ 0.00%
-+ 0.00%

2 Game-Changing AI Stocks That Can Plunge 48% and 54%, According to Select Wall Street Analysts

The Motley Fool·09/18/2026 11:26:01
Listen to the news

Key Points

  • AI has been the stock market’s leading catalyst over the last four years, with investors wanting their piece of a multitrillion-dollar opportunity.

  • According to one analyst, the wind could leave the sails of Wall Street’s hottest initial public offering in short order.

  • Meanwhile, valuation is an unmistakable concern for a high-flying AI applications stock.

Over the last four years, the artificial intelligence (AI) revolution has reshaped Wall Street. Providing software and systems with the tools to make autonomous, split-second decisions is a multitrillion-dollar global opportunity, and investors want their piece of the pie.

While most Wall Street analysts are overwhelmingly bullish regarding the AI infrastructure build-out, optimism isn't universal. According to select analysts, two of the most widely owned AI stocks, Space Exploration Technologies (SpaceX) (NASDAQ:SPCX) and Palantir Technologies (NASDAQ:PLTR), can plunge 48% and 54%, respectively, over the next year.

Missed Nvidia in 2009? This Rare Signal Is Flashing Again. In 2009, a "Double Down" signal flashed for a little-known chipmaker called Nvidia. For the first time in years, that same "Total Conviction" signal is flashing for a company 1/100th the size of Nvidia. Continue »

A twenty-dollar bill paper airplane that's crashed and crumpled into a financial newspaper.

Image source: Getty Images.

SpaceX: Implied downside of 48%

Considering that Elon Musk's space infrastructure and AI conglomerate had 21 underwriters, all of which received shares, it's not surprising that buy ratings outpace sell ratings by a substantial sum. Nevertheless, analyst Glenn Thum of Phillip Securities slapped a sell rating and a $75 price target on shares of SpaceX.

Thum's low-water price target for Space Exploration Technologies primarily concerns its AI-driven operations. Although SpaceX's mile-long prospectus assigned a $28.5 trillion addressable market to AI, Thum notes that this segment's otherworldly spending and steep losses aren't yet worthy of a valuation premium.

Additionally, Thum's research note cautions that SpaceX's major compute deals with Alphabet (NASDAQ:GOOGL)(NASDAQ:GOOG) and Anthropic will expire in late 2029 and can be terminated by either party after this year with 90 days' notice. In other words, xAI's long-term growth and profitability are far from assured.

Don't overlook SpaceX's staggered and accelerated share-unlock period, either. Whereas most initial public offerings prohibit insiders from selling shares for 180 calendar days post-debut, early-release-eligible SpaceX insiders can sell some of their shares to retail investors at several earnings- and time-based events. The steady increase in the company's float would be expected to weigh on its share price through at least mid-December.

Military personnel overseeing operations at a high-tech command center.

Image source: Getty Images.

Palantir Technologies: Implied downside of 54%

The other game-changing AI stock that can plunge, according to at least one Wall Street analyst, is AI-driven software-as-a-service (SaaS) provider Palantir Technologies.

Jefferies (NYSE:JEF) analyst Brent Thill raised his firm's price target on Palantir in early August from $70 to $80. The problem is that Palantir shares ended the Sept. 15 trading session at $172.56, implying 54% downside from Thill's call.

Thill's primary issue with Palantir is a common theme among Palantir skeptics: its valuation.

On the one hand, Palantir brings clearly defined competitive advantages to the table. Its Gotham SaaS platform has no large-scale competitors and assists the U.S. government and its allies in planning and overseeing military operations. This contract gravy train has allowed Palantir CEO Alex Karp to raise full-year sales guidance every quarter.

PLTR PS Ratio Chart

PLTR PS Ratio data by YCharts

On the flipside, history shows that price-to-sales (P/S) ratios above 30 aren't sustainable for companies at the forefront of innovative trends. Palantir entered 2026 with a P/S ratio above 100, and even with its outsize revenue growth is still sporting a trailing 12-month P/S ratio of 72. This is indicative of a bubble.

While Gotham's multiyear contracts would temporarily buoy Palantir if an AI bubble were to form and burst, the company's stratospheric valuation would make it a prime target during a bubble-bursting event.

Sean Williams has positions in Alphabet. The Motley Fool has positions in and recommends Alphabet, Jefferies Financial Group, and Palantir Technologies. The Motley Fool has a disclosure policy.