IG Group Holdings shares fell 21% to 1,016p after the online trading platform cut its 2026 revenue and margin guidance.
Peel Hunt, which rates the FTSE 100 group a 'hold' with a 1,100p target, calculates the warning could mean a high-teens percentage cut to market forecasts for 2026 EBITDA.
EBITDA is earnings before interest, tax, depreciation and amortisation, a common measure of operating profit.
IG now expects revenue to grow by a mid-single-digit percentage this year, against previous guidance of 10% to 15% and market expectations of about 12%.
It also guided to an EBITDA margin in the low 40s, as a percentage of revenue, below consensus of 45.5%.
Peel Hunt pinned the downgrade on weaker-than-expected retention in over-the-counter (OTC) derivatives, such as contracts for difference, which customers trade directly with IG rather than on an exchange.
Retention slips
IG kept about 70% of client trading income in these products as revenue in the third quarter.
That compares with a roughly 80% average since it overhauled its market-making in the second half of 2025.
Third-quarter revenue is expected to be about £240 million, down 14% on a year earlier.
The guidance had been raised in May and reaffirmed as recently as July.
Breon Corcoran, chief executive, blamed less supportive market conditions and said he remained confident of meeting medium-term guidance.
That target is organic revenue growth of at least 10% a year beyond 2026.
Customers keep coming
Peel Hunt still sees encouraging underlying trends despite the revenue miss.
Organic first trades rose more than 25% in the quarter, active customers increased about 17% and OTC customer income grew about 8%.
Underdog, the US fantasy sports and prediction markets business IG is buying, more than doubled net revenue to over $105 million.
The broker said those figures suggest customer acquisition, engagement and wider business momentum remain healthy.
Even after the fall, its 1,100p target sits about 8% above the current share price.
IG will give more detail alongside a strategy update on 22 October.
