On 29 April, GSK's shares fell as much as 8.8% in London — their steepest dive in almost two years per Bloomberg — and the trigger was not a miss. First-quarter earnings came in ahead of expectations, and investors decided the beat was made of the wrong material . The American depositary shares, each representing two ordinary shares, closed at $49.51 on 16 October, roughly a fifth below the $61.70 high struck earlier in 2026 .
GSK sells three things. Specialty Medicines — HIV, respiratory and immunology, and oncology — is the growth engine and did £3.8 billion in the June quarter, up 14% at constant exchange rates. Vaccines, built on the shingles vaccine Shingrix, the meningitis franchises and the RSV shot Arexvy, did £2.3 billion. General Medicines, the legacy portfolio led by the inhaled respiratory brand Trelegy, did £2.3 billion and shrank 9% . Just over half of group turnover is American: the US was £4,308 million of the £8,409 million quarter, with Europe at £2,042 million and International at £2,059 million .
The argument here is narrow. Over the same months in which the shares de-rated, the sell-side's long-range forecasts for this company moved sharply up — by roughly £4 billion of 2031 revenue and several points of operating margin through the patent cliff. Estimates rose; the multiple fell. Two FDA decisions and one reimbursement unlock inside the next six weeks are the nearest-term evidence that could force the gap closed.
Specialty Medicines carries the growth; the other two segments are a headwind
The composition complaint that broke the stock in April has a real basis, and it is worth stating before defending the stock. General Medicines is in structural retreat — Trelegy fell 7% in the second quarter, with channel-mix pricing adjustments alone clipping five points off its growth, and General Medicines in the US...