Nasdaq Biotech Soars on Rare Disease Drug Hopes, Market Cap Rises by $500 Billion in a Day

US rare‐disease biotech Scholar Rock Holding Corporation (NASDAQ: SRRK) closed at $49.99 on the Nasdaq, up 5.62%. Trading volume was about 1.66 million shares, and its market capitalization rose to roughly $5.99 billion (approximately KRW 8.4 trillion), adding about $357 million (over KRW 500 billion) in a single day.

In its recent Q1 2026 earnings release, the company reaffirmed statistically significant results from the Phase 3 SAPPHIRE trial of its spinal muscular atrophy (SMA) treatment apitegromab. With the FDA having set the PDUFA date for the new drug’s review, Scholar Rock said it is preparing to bring a second commercial manufacturing facility online in early Q3 2026. The company also noted that, as of the first quarter, it had increased its cash and cash equivalents to about $480 million and restructured existing debt through a new financing agreement with Blue Owl Capital, securing the necessary funds ahead of apitegromab’s launch.

Based in Cambridge, Massachusetts, Scholar Rock is a clinical-stage biotech developing antibody-based therapies that regulate growth-factor protein signaling, targeting rare and severe muscle and neuromuscular diseases. Its lead candidate, apitegromab, is the world’s first promyostatin-targeting monoclonal antibody designed to inhibit the activation of myostatin—a key regulator of muscle growth—and is drawing investor interest as a potential blockbuster to improve muscle strength and motor function in SMA patients.