Shares of Marvell Technology surged 4.6% in pre-market trading to $302.92 on June 18, as investors position ahead of the chipmaker's formal entry into the S&P 500 on June 22. The rally caps a remarkable stretch: the custom chipmaker's shares are up nearly 240% year to date , powered by an AI infrastructure boom and a one-two punch of catalysts that have remade its investor base almost overnight.

  • Index Funds Will Be Forced to Buy — Ready or Not. When a company joins the S&P 500, the index funds and ETFs that track the benchmark must hold it in proportion to its index weight — those funds collectively manage trillions of dollars, so an addition forces a wave of buying regardless of what managers think of the stock's valuation. That mechanical demand explains much of this week's strength. But the expected demand is often already priced in once an addition is announced, and stocks can fall after inclusion — a risk buyers at these levels are accepting.

  • Nvidia Put $2 Billion Where Jensen Huang's Mouth Is. At the Computex trade show in Taipei, Nvidia CEO Jensen Huang joined Marvell CEO Matthew Murphy on stage and declared: "The next trillion-dollar company, ladies and gentlemen."

The endorsement landed with extra force because Nvidia had recently invested $2 billion in Marvell, turning a CEO compliment into something closer to an industrial alliance. For shareholders, the partnership signals that Marvell's networking chips and custom processors are becoming essential plumbing inside Nvidia-powered data centers.

  • The Growth Is Real, but the Price Tag Is Steep. Marvell's fiscal 2026 data center revenue reached a record $6.1 billion, and custom chip work alone scaled to a $1.5 billion annual run rate across 18 cloud-provider design wins.

First-quarter data center revenue rose 27% year-over-year. Yet Marvell trades at a trailing price-to-earnings ratio of roughly 98x — meaning investors are paying nearly 100 years' worth of current profits for each share. That valuation assumes explosive earnings growth for years to come.

  • Insiders Have Been Selling Into the Rally. Insider activity shows $32 million in shares sold over the past three months , a pattern worth watching. When company executives reduce their own stakes while outside investors pile in, it can signal that management considers the stock fully valued — even if the business outlook remains strong.

The bottom line: Marvell's index inclusion and Nvidia alliance validate its position at the center of AI infrastructure. But at nearly 100 times earnings, the stock now prices in a future that must go almost perfectly right.