BioCryst Pharmaceuticals enters late May with short sellers holding a firm grip — and the cost to maintain that position just jumped sharply.
Short interest is running near 18% of the free float, a level that has barely budged over the past three months. The more striking development this week is in the cost to borrow. It has rocketed more than 100% over seven days to 4.38%, and is up nearly 800% over the past month. That kind of acceleration in borrow cost suggests a recent scramble for short positions in the lending market — and it follows a period in late April when short interest jumped by roughly 7 percentage points in a single session. Short sellers who arrived in that wave are now paying materially more to stay in the trade. Availability remains comfortable at around 420% of short interest, which means the lending pool is not close to exhausted — but the direction of travel on cost is worth watching.
Options positioning adds a contrasting angle. The put/call ratio is essentially flat against its 20-day average — 0.25 versus a mean of 0.24 — and the z-score is near zero. The annual range runs from 0.11 to 0.37, putting the current reading toward the middle. Call open interest is clearly dominating, meaning options traders are not treating this as a setup for a sharp downside move, even as short sellers remain heavily positioned. That divergence — heavy short interest alongside call-skewed options activity — is the core tension in BCRX's positioning right now.
The analyst community struck a mixed tone after the May 6 earnings print. Citizens raised its target to $28 while keeping the stock at Market Outperform. Wedbush and Needham both trimmed their targets — to $21 and $16 respectively — while holding positive ratings. The average target across the Street is $21.50, implying more than 150% upside to the $8.47 close. That gap is large enough to warrant caution — it may reflect optimistic base cases discounting future pipeline milestones rather than near-term fundamentals. EPS momentum scores are strong, ranking in the 86th percentile on a 90-day basis, and the earnings yield factor ranks in the 84th percentile. Those are genuine positives. The ORTEX short score of 65, however, signals that the aggregate short-side picture remains elevated even though the factor has softened slightly from a recent high of 66 on May 14.
Insider activity has been one-directional for months. The Chief Legal Officer sold shares on three separate occasions since December, and CEO Jon Stonehouse sold roughly 306,000 shares in March at $8.64. The net 90-day insider position is a sale of around 580,000 shares worth roughly $5.2 million. The trades are not panic-sized relative to the company's float, but there are no offsetting purchases from any executive. BlackRock added 1.5 million shares as of April 30, and State Street added a further 1.1 million — passive index flows likely driving both. Among active managers, Perceptive Advisors built a new position of 4.3 million shares and Vestal Point Capital added 4.8 million, providing a counterweight to the insider selling.
The most recent earnings print on May 6 produced a modest 1-day decline of 1.4%, followed by a five-day gain of 6.3%. The prior print in early May 2026 showed a similar pattern — a small negative day-one reaction that gave way to recovery. That two-event sample suggests post-earnings dips have attracted buyers rather than sellers. The next scheduled report is August 5.
The stock is down 3.4% on the week and 5.3% over the past month, trading at $8.47. Several correlated peers have moved more sharply in both directions — TXTM fell 12% on the week while MPLT gained 11% — suggesting the cohort is dispersing on stock-specific news rather than sector-wide flows. For BCRX, the borrow cost acceleration is the number to track: if it continues higher while short interest holds elevated, the squeeze arithmetic gets progressively tighter for those shorts, even with the lending pool still well-supplied.
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