SLS Borrow Market Hits Maximum Stress — Zero Availability, 149% Cost

SELLAS Life Sciences has crossed into territory where the lending market offers almost nothing to new short sellers. Availability has collapsed to 0.04% — effectively zero. Every share in the lending pool is now out on loan.

The cost to borrow has followed the supply shock straight up.

The Borrow Squeeze in Numbers

Cost to borrow stood near 14–16% through most of May. It sat at 22% on June 19. By June 26 it had reached 149.4% — a 572% weekly rise and a 919% move over the past month.

Availability has declined in lockstep. It was around 9–13% in late May. It dropped to 5% by June 19. On June 26 it hit 0.04% — the lowest reading in 52 weeks.

That combination — near-zero availability and triple-digit borrow cost — is the signature of a fully stressed lending market.

Short Interest at 44.7% of Float

Short interest sits at 44.7% of free float, up 10.5% in the past week. Official FINRA data put it at 63.4 million shares as of June 15, with days-to-cover at 9.25. That is a large, sticky short position in a stock up 54% over the past month.

When a heavily shorted stock rallies this sharply and the borrow pool simultaneously dries up, existing shorts face two compounding pressures. Their positions are underwater. And the shares they need to close are now the hardest — and most expensive — to return.

Options Market Reacts

The put-call ratio reached 0.29 on June 26, a 52-week high and a z-score of 2.3 above the 20-day mean. Put activity rising alongside a rally is consistent with short sellers hedging through options rather than covering outright — a logical response when the stock is near-impossible to borrow.

Short Score Confirms Severity

The ORTEX short score reached 93.3 on June 26, up from 85.3 a week earlier. The utilization rank sits at the 2nd percentile and the days-to-cover rank at the 9th — both deep in the extreme zone. These factor scores reflect the same stress visible in the raw lending data.

Earnings are next scheduled for August 10.

---

• SI % of FF: 44.7%, up 10.5% week-on-week
• Cost to borrow: 149.4%, up 572% in one week, up 919% in one month
• Availability: 0.04% — 52-week low
• Stock price: $12.39, +54% over one week, +53% over one month
• PCR: 0.29, 52-week high, z-score +2.3
• ORTEX short score: 93.3 — up from 85.3 seven days ago
• Next earnings: August 10, 2026