SLS Short Interest Hits All-Time High: Sellas Bulls Smell A Short Squeeze As Executive Contract Changes Fuel Buyout Chatter

• Sellas announced changes to the structure of severance payments to CEO Angelos Stergiou, CFO John Burns and chief development officer Dragan Cicic.
• Sellas’ Phase 3 Regal trial evaluating Galinpepimut-S in AML patients remains the key catalyst.
• SLS stock is on track to record its strongest weekly performance in six weeks.

Shares of Sellas Life Sciences Group (SLS) grabbed Wall Street’s attention on Friday as short interest climbed to a record, amid renewed buyout speculation following changes to executive severance agreements and ahead of a closely watched update from the company’s acute myeloid leukemia trial.

SLS shares climbed higher in pre-market trading following a near 15% surge in the previous session.

Short Interest Buildup After Strong Rally

According to Koyfin data, short interest in SLS climbed to nearly 33% of the float as of June 15, up sharply from 25.5% at the start of April and 28.4% at the beginning of the year. The company has roughly 186 million outstanding shares.

SLS has attracted strong investor interest in recent sessions, putting the stock on track for a seventh consecutive day of gains. It is also set to record its strongest weekly performance in six weeks.

SELLAS Stock Jumps After Executive Severance Changes

According to an SEC filing on Thursday, Sellas announced the amendment of CEO Angelos Stergiou’s employment agreement to allow eligible severance payments triggered by a change in control to be paid as a single lump sum rather than in installments.

Meanwhile, CFO John Burns and Chief Development Officer Dragan Cicic signed new severance agreements that provide enhanced benefits if they are terminated following a change in control, including a lump-sum payment equal to 15 months of base salary, their full target annual bonus, and accelerated vesting of unvested equity awards.

SLS Bulls Eye Buyout, Short Squeeze Triggers

Retail sentiment on Stocktwits turned ‘bullish’ from ‘neutral’ a day earlier, while message volumes increased by 250% over a 24-hour period. SLS was also among the top trending tickers at the time of writing.

Chatter on the platform primarily focused on the speculation of a buyout, given the latest executive contracts update, as well as a potential short squeeze.

One user said the “short squeeze set up is real.”

Another user added that the executives are “positioning their personal equity ahead of a major corporate pivot.”

AML Trial Remains Key Catalyst

Investors are keenly awaiting updates on the biotech firm’s Phase 3 Regal trial evaluating Galinpepimut-S (GPS) in AML patients in remission after relapse. The study is approaching the 80-event (deaths) threshold required for the final overall survival analysis, with the company previously reporting 72 events as of Dec. 26, 2025.

Separately, its second drug candidate, SLS009, has delivered encouraging mid-stage results in relapsed/refractory AML and is now being tested in newly diagnosed patients, with topline data expected in the fourth quarter of 2026.

SLS shares have soared 140% so far this year.

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