NRIX: High Short Interest Meets a Bullish Option Market

Nurix Therapeutics enters November with a notable contradiction: short sellers hold 20% of the free float, yet options traders have rarely looked more bullish.

Short interest at 20.2% of free float is genuinely elevated. It climbed roughly 3 percentage points through late October, jumping from around 17.5% to current levels in a single week at the end of October. FINRA's fortnightly settlement data pegged the short position at 20.6 million shares as of October 15, with days-to-cover running at 9.2 days. That is not a small or casual bearish bet. What makes the picture unusual is that the borrow market has not tightened to match the conviction. Availability is exceptionally loose at 3,326%, meaning roughly 61.8 million shares remain available to lend against 20.4 million already borrowed. Cost to borrow has doubled over the past week to 0.80%, a sharp move in percentage terms, but from a very low base. These are not the conditions of a trapped short, they describe a heavily shorted stock where bears can still get in and out freely.

Options traders are reading the situation entirely differently. The put/call ratio has dropped sharply to 0.57, running 1.6 standard deviations below its 20-day mean of 0.76. That is the most call-heavy positioning of the past year, with the PCR close to its 52-week low of 0.07. A month ago the ratio was sitting above 0.90, firmly in defensive territory. The rotation from puts to calls over October is striking. It suggests a subset of market participants has turned notably more optimistic even as the short position grew.

The analyst community broadly agrees with the bulls. All recent changes have kept Buy or Outperform ratings in place, and the consensus mean price target of $33.86 implies roughly 31% upside from the current price of $25.82. Wells Fargo trimmed its target from $25 to $20 this week while maintaining Overweight, the only sour note in an otherwise constructive cluster of October revisions that included target raises from Baird and Oppenheimer. The bull case centres on the BTK degrader bexobrutideg advancing through registrational studies while expanding into inflammatory disease indications, alongside a strong cash position of around $1.1 billion, which the company says covers its runway into the second half of 2029. The bear case is concentrated on a single point: if bexobrutideg fails on efficacy or safety, the valuation collapses to a cash story with little residual credit for the pipeline.

Institutional ownership reinforces the sense that sophisticated long-only money has committed. BlackRock holds 8.8 million shares at 8% of the float. Deep Track Capital added 2.2 million shares to reach 7.1%, Rubric Capital built a 4.8 million share position, and Perceptive Advisors disclosed an entirely new 5.5 million share stake as of September. T. Rowe Price added 2.1 million shares over the same period to reach approximately 5%. The scale of these Q2 and Q3 builds is notable for a clinical-stage biotech, though all 13D/G figures are as last disclosed around the 5% threshold and positions may have changed since. Insider activity over the past 90 days is modestly net negative at a loss of roughly $1.5 million, but the recent transactions are largely option exercises paired with same-day sales, the standard compensation mechanics rather than a discretionary signal.

One data point worth watching separately: ORTEX's Wikipedia and ORTEX page-view data showed a retail attention z-score of 6.3 as of October 19, an unusually high spike in public interest. That dataset is a measure of attention, not a revenue indicator, but attention spikes of that magnitude in clinical-stage biotech often accompany data or partnership news.

The next scheduled earnings event is January 28, 2027, 85 days away, which removes an immediate binary catalyst. The key question for the weeks ahead is whether the short position begins to unwind given the loose borrow market and rising call activity, or whether it reflects informed pessimism about an upcoming clinical update that the options market has yet to price.