Why Cathie Wood Just Sold Millions in Iridium and Bought This Biotech Stock

Cathie Wood's ARK Invest just executed a major portfolio pivot—dumping millions in satellite stalwart Iridium to double down on a high-risk, high-reward biotech play.

ARK's Big Bet on Biology

The move signals a stark shift in conviction. Wood's team bypassed the steady, predictable cash flows of a communications infrastructure company to chase the explosive potential of genomic medicine. It's a classic growth-at-any-price maneuver, betting that a single drug approval could deliver returns that decades of satellite subscription revenue can't match.

The Calculus of Conviction

This isn't just a trade; it's a statement. Selling a profitable, established business to fund a preclinical or early-stage biotech firm requires near-religious faith in disruptive innovation. The math is brutal: for every ten such bets, nine might flame out. But the one that hits could return the entire fund. It's a strategy that makes traditional income investors queasy—and occasionally makes geniuses out of its architects.

Wood's signature move—loading up on volatility while the street hunts for safety—highlights a deepening divide in market philosophy. While Wall Street frets over Fed meetings and PE ratios, ARK is digging into pipeline data and Phase II trial results. Sometimes you make money on the boring, reliable stuff. And sometimes you make fortunes by betting on miracles that haven't happened yet. Just ask any crypto veteran about the feeling.

TLDR

• Cathie Wood’s ARK Invest sold 176,093 shares of Iridium Communications across three ETFs worth $3.32 million after the stock jumped 6.3%
• ARK purchased 11,342 shares of Nurix Therapeutics valued at $221,736 following positive Phase 1 clinical trial data
• ARK sold 4,166 shares of Teradyne worth $833,075 and 35,379 shares of Adaptive Biotechnologies worth $525,731
• Wood reduced positions in Ibotta with sales of 11,700 shares totaling $266,292 across multiple ETFs
• The moves show ARK shifting focus toward biotech investments while trimming technology and communications holdings

Cathie Wood’s ARK Invest made several portfolio changes on Wednesday, December 10, 2025. The fund manager sold and bought shares across multiple exchange-traded funds as part of her ongoing investment strategy.

The largest transaction involved Iridium Communications. ARK sold 176,093 shares of the satellite communications company across three funds. The sales happened through ARK Innovation ETF, ARK Autonomous Technology & Robotics ETF, and ARK Space Exploration & Innovation ETF.

Iridium Communications Inc., IRDM

The total value of the Iridium sale reached approximately $3.32 million. The selling came after Iridium’s stock price increased 6.3% during trading. Wood has been reducing her Iridium position consistently over recent weeks.

ARK also sold shares of Teradyne on the same day. The ARK Autonomous Technology & Robotics ETF offloaded 4,166 shares of the automated test equipment company. This transaction totaled $833,075 in value.

The fund made another large sale in the biotech sector. ARK Genomic Revolution ETF sold 35,379 shares of Adaptive Biotechnologies. The diagnostics company’s shares had risen 5.9% before the sale, which was worth $525,731.

ARK Reduces Mobile Technology Holdings

Cathie Wood continued trimming exposure to Ibotta. The mobile technology company saw ARK sell 11,700 shares across multiple ETFs. The combined sales of Ibotta stock totaled $266,292.

On the buying side, ARK made one purchase during Wednesday’s trading. The fund acquired 11,342 shares of Nurix Therapeutics through the ARK Genomic Revolution ETF. The purchase was valued at $221,736.

Nurix Therapeutics, Inc., NRIX

Biotech Investment Follows Clinical Trial Results

Nurix Therapeutics recently shared results from a Phase 1 clinical study. The biotech company presented data on its Bruton’s tyrosine kinase degrader called bexobrutideg at the American Society of Hematology Annual Meeting. The experimental drug is being tested for treatment of blood cancers.

The trading activity shows ARK moving capital between different sectors. The fund sold shares in communications and technology companies while adding to its biotech holdings. These changes reflect Wood’s approach to managing the portfolio across her various ETFs.

ARK has been selling Iridium shares for multiple days in a row. The same pattern applies to Adaptive Biotechnologies and Ibotta. This indicates Wood is making deliberate moves to reduce these positions over time rather than exiting all at once.

The Wednesday trades involved five different ARK ETFs. These included funds focused on innovation, robotics, space exploration, and genomics. Each fund holds different combinations of stocks based on its investment focus.