Nvidia, Palantir, and Broadcom Are Sending Shockwaves Through Wall Street With This $4.6 Billion Warning

By Sean Williams – May 4, 2026 at 4:06AM ESTKey PointsThe AI revolution is a multitrillion-dollar opportunity being led by Nvidia, Palantir Technologies, and Broadcom. Form 4 filings with regulators show that AI insiders have been heavy net sellers of their company's stock.Additionally, a time-tested valuation metric points to this AI trio being historically expensive. Nothing has captured the attention of investors since the advent and proliferation of the internet in the mid-1990s quite like the rise of artificial intelligence (AI). Empowering software and systems with the tools to make split-second, autonomous decisions is a multitrillion-dollar addressable market. Arguably, no companies have benefited more from the evolution of AI than graphics processing unit (GPU) titan Nvidia (NVDA 0.48%), data-mining specialist Palantir Technologies (PLTR +3.57%), and networking solutions kingpin Broadcom (AVGO +0.88%). Broadcom joined the trillion-dollar club in December 2024, Nvidia became the first public company to top $5 trillion in October 2025, and Palantir shares have skyrocketed 2,100% since the end of 2022. While all three companies possess undeniable competitive advantages, the people who know these businesses best are sending worrisome signals. Image source: Getty Images. Insiders are sending a message -- are you paying attention? No group understands a company better than its insiders. An "insider" is a high-ranking executive, board member, or beneficial owner of at least 10% of a company's outstanding shares. These are individuals who may possess non-public information. Insiders are required by law to file Form 4 with regulators anytime they purchase or sell shares of their company, including the exercising of option contracts. This filing has to be made within two business days of a transaction. Based on aggregated Form 4 filings over the trailing year (as of April 28, 2026), insiders at these AI juggernauts have sent shockwaves through Wall Street with their heavy net-selling activity: Nvidia: $2,396,602,073 in net selling Palantir: $1,058,424,816 in net selling Broadcom: $1,144,516,490 in net selling Collectively, the hardware, networking, and application companies leading the AI revolution have seen their insiders dispose of approximately $4.6 billion in shares over the trailing 12 months. ExpandNASDAQ: NVDANvidiaToday's Change(-0.48%) $-0.96Current Price$198.61Key Data PointsMarket Cap$4.8TDay's Range$197.13 - $202.9552wk Range$110.82 - $216.82Volume4.5MAvg Vol175MGross Margin71.07%Dividend Yield0.02% The caveat to this data is that not all insider sales are inherently nefarious. Since most high-ranking executives and board members receive the bulk of their compensation as stock or options, they often sell shares of their company's stock to cover their federal and/or state tax liability. There are several reasons to sell a stock, and tax-based selling isn't something investors should be worried about. But the other side of this coin is just as important. Whereas several reasons exist to sell a stock, there's only one reason to be a buyer: the belief that shares will appreciate. Nvidia hasn't had a single insider purchase over the trailing year, while Palantir's and Broadcom's insiders have scooped up just $3.32 million and $1.55 million in shares, respectively. Insiders aren't buying, which may signal that the people who know these companies best don't view their stock as a bargain. ExpandNASDAQ: PLTRPalantir TechnologiesToday's Change(3.57%) $4.96Current Price$144.07Key Data PointsMarket Cap$345BDay's Range$141.39 - $146.4452wk Range$105.32 - $207.52Volume495KAvg Vol52MGross Margin82.37% The time-tested price-to-sales (P/S) ratio strongly suggests this AI trio is historically expensive. Over the last three decades, P/S ratios above 30 for companies at the forefront of next-big-thing trends have signaled the presence of a bubble. As of the closing bell on April 28, Nvidia, Broadcom, and Palantir had respective trailing 12-month P/S ratios of 24, 28, and 81. Executives at Nvidia, Palantir, and Broadcom may be optimistic about their company's future, but their actions say otherwise.Read NextMay 3, 2026 •By Chris Neiger3 Surprising Quantum Computing Stocks Robinhood Investors LoveMay 3, 2026 •By Ryan VanzoNvidia Has Split Its Stock 480-for-1 Since 2000. Here's When to Expect the Next Stock Split.May 3, 2026 •By Ryan VanzoThe SpaceX IPO Will Create a $75 Billion Spending Spree -- These 2 AI Stocks Will WinMay 3, 2026 •By Keithen DruryGot $1,000?

Here Are Three Incredible AI Stocks to Get StartedMay 3, 2026 •By John BromelsJensen Huang Just Announced Something Big. Here's What It Means for Nvidia Stock.May 3, 2026 •By Scott LevineStock Market Indexes Explained: What They Are and Why They MatterAbout the AuthorSean Williams is a data-driven Motley Fool contributing analyst who's been investing for 27 years and has penned north of 15,000 articles. You'll find him at the intersection of politics and investing tackling macroeconomic topics of interest (Social Security and Donald Trump's economic/tax policies), analyzing which stocks billionaire investors (e.g., Warren Buffett) are buying and selling, and digging into how the world's most-influential businesses and trends -- everything from the evolution of artificial intelligence (AI) to the next stock split -- are changing Wall Street. He holds a B.A. in Economics from the University of California, San Diego.TMFUltraLongX@AMCScamStocks MentionedNvidiaNASDAQ: NVDA$198.61(-0.48%)-$0.96BroadcomNASDAQ: AVGO$421.09(+0.88%)+$3.66Palantir TechnologiesNASDAQ: PLTR$144.07(+3.57%)+$4.96*Average returns of all recommendations since inception. Cost basis and return based on previous market day close.