Y-mAbs Therapeutics stock exits after USD 412.0 million deal

Y-mAbs Therapeutics stock exited the public market after SERB Pharmaceuticals completed its USD 412.0 million acquisition on September 16, 2025. The transaction transferred the cancer biotechnology company into private ownership and ended the listed equity story for investors tracking ticker YMAB.

Cash deal ended the listing

According to Y-mAbs, SERB paid USD 8.60 per share in the all-cash transaction. The offer represented a 105 percent premium to the unaffected share price, making the acquisition the decisive valuation event for holders.

The company said the transaction included DANYELZA, its approved antibody-based treatment for pediatric patients with high-risk relapsed or refractory neuroblastoma. That commercial asset formed the main strategic link between Y-mAbs and SERB's rare-disease portfolio.

Revenue had already reached scale

Y-mAbs reported total revenue of USD 19.5 million for the second quarter of 2025, according to its investor-relations release. The result exceeded the company's guidance range of USD 17 million to USD 19 million by USD 0.5 million at the upper end.

The earlier first quarter also produced USD 20.9 million in net product revenue, an 8 percent year-over-year increase. These figures show a commercial business with measurable product sales before the acquisition changed the ownership structure.

What remains for former holders

Robinhood lists Y-mAbs as a completed cash merger and states that shares were removed while holders received USD 8.6000 per share. The key reference for former investors is therefore the completed cash consideration rather than a continuing Nasdaq quotation.

Y-mAbs entered the deal with a revenue-generating oncology product, a clinical pipeline and a second-quarter revenue figure above guidance. The acquisition converted those operating milestones into a fixed cash outcome of USD 8.60 per share.