Short sellers are exiting APLS at pace. Short interest dropped 32% in a single week to 7.1% of free float — and is down 56% over the past month. The context is clear: Biogen is acquiring Apellis Pharmaceuticals for $41 per share in cash, plus contingent value rights tied to sales milestones for SYFOVRE and EMPAVELI.
From a peak above 17% of float in mid-April, short interest has been cut by more than half. The steepest drop came in the week ending May 13, when roughly 4 million shares were returned. The stock is trading at $41.03 — essentially pinned to the deal price.
That dynamic explains the lending market too. Cost to borrow fell to 0.64%, down from the multi-percent spikes seen in early April when the deal was first digested by the market. At that point, CTB briefly hit 6.93% on April 6 before collapsing as the arbitrage picture clarified. Today, availability is loose. There is little incentive to maintain a short position against a cash deal with a fixed price.
The ORTEX short score has tracked the unwind precisely. It stood at 51.9 on May 1. It has declined steadily each session since, reaching 47.4 by May 13.
One signal stands apart from the orderly unwind. The put/call ratio hit 0.90 on May 13 — a z-score of 3.2 standard deviations above the 20-day mean of 0.70. That is the highest options-market bearish skew in weeks, and it sits close to the 52-week high of 1.06.
In a deal-pinned name, elevated put buying typically reflects one of two things: merger-arb hedging against deal break risk, or positioning around the contingent value rights. The CVRs tied to SYFOVRE and EMPAVELI revenue milestones introduce binary outcomes that options can price. Analyst sentiment offers context here — the consensus is "hold" across 18 of 20 covering analysts, with the mean price target at $40.93. Almost every major firm cut ratings on April 1 as the deal news landed: JP Morgan, Citigroup, Raymond James, Cantor Fitzgerald, Needham, and HC Wainwright all downgraded on the same day.
On the institutional side, BlackRock added nearly 7 million shares as of April 30 — bringing its holding to 13.2 million shares, or 10.3% of the company. State Street also added 937,000 shares in the same reporting period. Passive index funds accumulating a deal target is not unusual, but the scale of the BlackRock build is notable.
Insider data is stale (last trade February 11) and carries low significance scores. The January cluster of executive sales — CEO, CFO, CSO, CMO, and CTO all sold on the same day — was routine plan selling at $21.75, well below the deal price.
See the live data behind this article on ORTEX.
Open APLS 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.
