Tango Therapeutics Stock Is Up 840%, and This Fund Just Disclosed Buying $164 Million More

On May 15, 2026, RTW Investments disclosed a major buy of Tango Therapeutics (NASDAQ:TNGX), acquiring 11,809,392 shares—an estimated $164.37 million trade based on quarterly average pricing.

What happened

According to a Securities and Exchange Commission (SEC) filing dated May 15, 2026, RTW Investments bought 11,809,392 shares of Tango Therapeutics (NASDAQ:TNGX), with the estimated transaction value at $164.37 million based on the quarter’s average share price. The fund’s quarter-end position value in the company increased by $265.04 million, a figure that reflects both the additional shares and the stock’s price movement.

What else to know

• RTW Investments increased its stake in Tango Therapeutics, bringing the position to roughly 3% of its 13F reportable assets under management.
• Top holdings after this filing:
  • NASDAQ:MDGL: $1.04 billion (10.4% of AUM)
  • NASDAQ:INSM: $791.91 million (7.9% of AUM)
  • NASDAQ:PTGX: $533.22 million (5.3% of AUM)
  • NASDAQ:PTCT: $527.76 million (5.3% of AUM)
  • NASDAQ:ARGX: $518.07 million (5.2% of AUM)
• As of Friday, shares of Tango Therapeutics were priced at $21.98, up a staggering 840% over the past year and well outperforming the S&P 500, which is up 28%.

Company Overview

Company Snapshot

• TNGX develops targeted oncology therapies, including TNG908 for cancers with methylthioadenosine phosphorylase deletions, and additional programs addressing BRCA1/2-mutant and STK11-mutant cancers.
• The firm has a strategic collaboration with Gilead Sciences for the discovery, development, and commercialization of cancer therapies.
• It is based in Cambridge, Massachusetts, with a focus on precision medicine for genetically defined cancers.

Tango Therapeutics, Inc. is a biotechnology company specializing in the discovery and development of precision cancer therapies. Leveraging synthetic lethality and strategic collaborations, the company advances a pipeline targeting genetically defined cancers.

What this transaction means for investors

RTW Investments specializes in biotechnology, so a buy of this size during such a staggering rally suggests the firm believes the most important value-creating events may still lie ahead.

The bull case seemingly revolves around vopimetostat, Tango's lead precision oncology candidate. Earlier this month, management said enrollment remains robust in ongoing combination studies targeting MTAP-deleted pancreatic and lung cancers, with initial safety and efficacy data expected later this year. CEO Malte Peters said the company remains encouraged by early results and is actively evaluating a path toward pivotal development in pancreatic cancer.

Importantly, Tango has the financial flexibility to pursue that strategy. The company ended the first quarter with $379.8 million in cash, cash equivalents, and marketable securities, which management believes is sufficient to fund operations into 2028 and beyond several anticipated clinical data readouts.

Like many development-stage biotech companies, Tango is not yet profitable. The firm’s first-quarter net loss widened to $45.5 million from $39.9 million a year earlier. But for investors, earnings are not the story right now; instead, how upcoming data validates growth will be key to future performance.

Jonathan Ponciano has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Argenx Se. The Motley Fool recommends Protagonist Therapeutics. The Motley Fool has a disclosure policy.