Glaukos (GKOS) shares plummeted 12% intraday after the company reported weaker-than-expected sequential revenue growth for its iDose product in Q4 2025, overshadowing its reaffirmed 2026 net sales guidance of $600 million to $620 million.

The medtech firm projected Q4 iDose sales of about $45 million, representing a 13% sequential increase from Q3, which fell short of some analysts' expectations. Needham analyst David Saxon noted that seasonal factors and a strong Q3 made the sequential growth appear weaker, but the market reacted negatively to the slowdown.

While Glaukos maintained its 2026 revenue outlook and reported strong preliminary Q4 net sales of $143 million (up 36% YoY), investors focused on the iDose performance, driving the stock lower.