AnaptysBio heads into the back half of June with its most striking divergence in months: options traders have turned sharply bullish while short sellers quietly add to one of biotech's larger short positions.
The options signal is the standout this week. The put/call ratio has collapsed to 0.61, nearly three standard deviations below its 20-day average of 2.03 — a swing so extreme it registers as the most call-heavy positioning in the past year, against a 52-week low of essentially zero and a high of 18.4. That mean of 2.03 is itself unusually elevated, reflecting persistent hedging that had built up through May and into early June. The abrupt shift over just the past two sessions — PCR ran at 2.04 through June 18, then dropped to 0.51 on June 22 and 0.61 on June 23 — points to new call buying rather than put expiry, and coincides with the stock's 3.2% weekly gain to $59.43.
Short interest tells a more stubborn story. Bears hold 17.6% of the free float short — a position that has grown 9.2% over the past month, adding roughly 400,000 shares to reach 4.87 million. The lending market, however, offers no friction to that thesis: availability is ample at 578%, meaning there are nearly six shares available to borrow for every share currently shorted, and cost to borrow has eased sharply to 0.42%, down 36% over the past month. The borrow pool has tightened this week — availability fell from over 1,000% as recently as June 17 — but remains loose enough that there is no squeeze pressure building. Short score has crept higher all week, reaching 64.2, its best level in recent weeks, but the short score rank of 19 out of 100 suggests this is a watched name rather than an extreme.
The Street remains constructive, though price targets have been through a volatile cycle. HC Wainwright assumed coverage on June 10 with a Buy and a $95 target. UBS and Barclays both raised targets in mid-May following the last earnings print — UBS to $76, Barclays to $75 — after having cut sharply in late April when both pulled targets down from the $79–$90 range. The consensus mean sits near $87, implying roughly 46% upside to current levels. The bull case centres on the $250 million Sagard Healthcare royalty deal, imsidolimab's BLA trajectory via Vanda, and GSK's Jemperli collaboration momentum. Bears point to litigation risk with GSK over the Jemperli licence and concentration in a handful of binary-outcome programmes. Valuation multiples support the Street's optimism on earnings quality — the EPS surprise factor scores in the 93rd percentile — though forward EPS momentum has faded sharply, ranking in the 12th percentile on a 30-day basis and the 3rd percentile on a 90-day view.
Institutional ownership adds an interesting wrinkle. EcoR1 Capital holds a concentrated 27.1% of shares — an unusually high anchor position for a name of this size — and held flat through Q1. Sirenia Capital Management built an entirely new 6.6% stake in Q1, and Affinity Asset Advisors added nearly 500,000 shares. On the other side, D.E. Shaw trimmed by 91,000 shares and First Light Asset Management cut by 81,000. The insider picture is less decisive: the most recent open-market activity was director selling in late March at prices around $56–$58, close to where the stock trades now, with June activity limited to routine equity awards.
AnaptysBio's next earnings event is scheduled for August 6. The past four prints have produced moves of -5.5%, -7.7%, +4.2%, and +10.3% the day after — an asymmetric distribution skewed toward sharp downside or sharp upside, with no muted reactions in the record. The August print arrives with options traders positioned for a rally, short sellers holding firm at elevated levels, and the imsidolimab BLA review timeline the key variable the market will be calibrating between now and then.
See the live data behind this article on ORTEX.
Open ANAB on ORTEX →ORTEX Market Intelligence content is generated by AI from a snapshot of ORTEX's proprietary data. Content is informational only and does not constitute investment advice.
