Gamma Investing cut its SLS stake by 259 shares, or 32%, holding 556 shares worth about $8,210 as of June 30.
- CoreCap Advisors moved in the opposite direction, reporting a new 690-share SLS position valued at about $10,180.
- Investors remain focused on Sellas’ Phase 3 Regal trial of GPS in AML, which has reached 78 of the 80 events needed for final analysis.
- Partnership and buyout chatter has grown around CEO Angelos Stergiou’s LinkedIn post and updated change-of-control terms.
Shares of Sellas Life Sciences (SLS) slid on Monday, with small institutional moves drawing attention ahead of a closely-watched update from its Regal acute myeloid leukemia (AML) trial.
SLS stock fell 3% on Monday, logging its second consecutive session in the red.
SLS Institutional Bets Split Ahead Of Regal Readout
Fresh Quiver Quantitative data showed split positioning among smaller institutional holders. Gamma Investing held 556 shares of SLS as of June 30 after cutting its stake by 259 shares, or 32%. The position was valued at about $8,210 and was reported late Tuesday. Meanwhile, CoreCap Advisors reported a new 690-share position worth about $10,180 as of June 30.
Sellas investors are focused on the company’s Phase 3 Regal trial of GPS (galinpepimut-S) in AML. The study has reached 78 of the 80 events needed to trigger its final analysis, putting the trial near the finish line. Sellas has previously said the Regal trial would be considered successful if GPS extends median overall survival to 12.6 months, compared with 8 months under standard treatment. CEO Angelos Stergiou has called the slower-than-expected accumulation of events encouraging.
SLS Buyout Chatter Builds
Traders have also been watching for signs of potential strategic interest after CEO Angelos Stergiou’s Fourth of July LinkedIn post referenced the company’s investigators, collaborators, strategic partners and shareholders, while striking an upbeat tone on the company’s future. The post did not signal a deal, but it added to partnership and buyout chatter as the AML trial nears final analysis.
Updated executive agreements have also become part of the discussion. Stergiou’s amended deal changes certain change-of-control severance payments to a lump sum, while CFO John Burns and Chief Development Officer Dragan Cicic would receive salary, bonus, COBRA support and full equity acceleration under qualifying change-of-control exits. These arrangements are not proof of deal talks, but investors are reading them against the backdrop of a major pending catalyst.
Sellas has already seen its market value rising from about $73 million at the start of 2024 to more than $1.5 billion by mid-2026. The company ended Q1 with $107.1 million in cash and added $28.7 million from warrant exercises in April and May. Shareholders also approved a 20 million-share increase to the 2023 Equity Incentive Plan, while Stergiou received 1.065 million restricted stock units, lifting his ownership to 1.76 million shares.
How Do Retail Traders Feel About SLS?
On Stocktwits, retail sentiment for SLS was ‘neutral’ amid ‘normal’ message volume.

One user said, “$SLS in my opinion, all warrants being exercise is a bigger PR than the 80th event! They’re both huge, but all warrants being exercise leaves infinite room to run! Things are lining up near perfectly!”
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Another user said, “$SLS 80 means FA and BO in a span of 3-6 weeks. Knowledge diffusion theory in effect. $13, $25, settle at $60-$100 then BO at $175! All within 6 weeks after 80 announcement.”
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SLS stock has surged 522% over the past year.
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