• One hedge fund cohort owns the Rasonque launch. Healthcare specialists hold a fifth of Revolution Medicines, more than every other hedge fund cohort combined. Rasonque, the company’s first approved drug and a pancreatic cancer treatment, booked $198 million in its first five weeks.

• Total hedge fund ownership obscures activity by fund type. Hedge funds own less of Revolution than they did before the April readout, but the sellers were quants, multi-managers and fundamental funds. Healthcare specialist funds added about 5.8 million shares through it.

• Shorts have rebuilt to 6.5% of float after losing about $2 billion since the start of 2025. They built ahead of the April readout and the August approval, and both times the stock rallied and they covered at a loss. This build has not been squeezed yet, and the longs against it are concentrated in a handful of specialist funds.

S3 Hedge Fund Cohort Dataset

S3’s Specialist Conviction in Biotech paper sorted U.S. biotech, pharma and life sciences stocks by how many healthcare specialist hedge funds held each one. From 2015 to mid-2026 the most specialist-held quintile returned 19.5% a year, against 8.0% for the universe and a loss for the least-held quintile. Revolution was the case study: it entered the top quintile of healthcare specialist fund count at $17 in May 2022 and never left.

Revolution Medicines (RVMD) Hedge Fund Positioning

Rasonque (daraxonrasib) was approved on August 26 for previously treated metastatic pancreatic cancer, and Revolution reported $198 million in first-five-week sales on November 5, beating expectations. Hedge funds appear to have taken profits: since March, they have gone from 37.5% to 33.2% of the company and from 142 funds holding to 122.

Underneath, healthcare specialists added 5.8 million shares and now hold 43 million, a fifth of the company and more than every other cohort combined. Fewer of them hold it, though: the count is down from its peak of 29 to 26. Every other cohort sold. Fundamental funds had nearly doubled their stake ahead of the April readout and gave 40% of it back into the approval, 10.4 million shares down to 6.1 million, though the number holding stayed at 38. Multi-managers cut their stake by about 40% and the number holding fell from 26 to 21. Quants cut theirs by a third and the number holding fell from 28 to 18. Event-driven funds, the second-largest holder with 6.4% of the company across eight funds, barely moved.

Taken as one number, hedge fund ownership of Revolution is down since March, by shares held and by funds holding alike. Taken by cohort, the sellers were quants, multi-managers and fundamental funds taking profits, and the buyer was the cohort with the best record in biotech, which now holds more of the company than the other hedge fund cohorts combined. Fewer hedge funds own Revolution than in March, but the ones that do have more conviction, and a few specialist funds now matter more to the stock than the hedge fund total does. That is the position the shorts are betting against.

The short side

Shorts built ahead of the April readout and again ahead of the August approval, and both times the stock rallied and they covered at a loss, taking short interest down to 5% of float. They have since rebuilt to 6.5% of float, and so far the stock has not run them over: it fell 7% while they built in late September and has since returned to where it started. The S3 Active Long-to-Short ratio is 6.4, nowhere near a battleground. What the ratio does not show is that the long side rests on one cohort, and on a handful of funds within it.

The healthcare specialist basket now

Over the paper’s eleven years, the most specialist-held quintile compounded 662% against 141% for the biotech universe, and its worst drawdown was 35%, against 47% for the universe. This fall has been a rough stretch for it. Rebuilt daily for 2026, the quintile led through the summer, up 35.1% at June 30 against 25.9% for the universe, then gave the lead back and more: it is now up 9.8% for the year against 19.2%, and has fallen 23.8% from its August high, almost twice the universe’s 12.9% decline. A setback of that size is still inside the quintile’s long-run range, but it puts pressure on the same funds that own a fifth of Revolution.

How to read Revolution Medicines (RVMD) positioning from here:

• Specialist count, now 26.

  Back to 29 means new specialists are arriving behind the launch; lower means conviction is narrowing to the funds already in.

• Fundamental cohort, now 38 funds.

  The largest hedge fund holder by count, up from 23 a year ago, but holding half the shares it did in March. If these funds leave, ownership narrows to the specialists and the eight event-driven funds.

• Shorts at 6.5% of float against an S3 Active Long-to-Short ratio of 6.4.

  A further build with the ratio falling would be the first sign hedge fund positioning is tilting bearish.

The information herein (some of which has been obtained from third party sources without verification) is believed by S3 Partners, LLC (“S3 Partners”) to be reliable and accurate. Neither S3 Partners nor any of its affiliates makes any representation as to the accuracy or completeness of the information herein or accepts liability arising from its use. Prior to making any decisions based on the information herein, you should determine, without reliance upon S3 Partners, the economic risks, and merits, as well as the legal, tax, accounting, and investment consequences, of such decisions.