London's retail trading giant just had its worst day in nearly a decade. IG Group shares crashed more than 27% on Friday after the FTSE 100 firm slashed its 2026 revenue growth forecast, blaming weak market conditions that hammered its over-the-counter derivatives business.

The numbers explain the panic. Third-quarter revenue is expected at about £240 million ($317 million), about 14% below last year's level, as OTC revenue retention slid to around 70%. Management now sees full-year 2026 revenue growing only by a mid-single-digit percent — a sharp comedown from its previous target at the upper end of mid-to-high single digits. By 0743 GMT the shares traded 23.8% lower at 975 pence, on track for the worst session since December 2016. The pain spread across the sector: peers Plus500 and CMC Markets dropped 7% to 10%.

Why it matters

IG is a bellwether for retail trading activity, so a miss this big says something about the whole market, not just one company. When volatility dries up and clients trade less, brokers feel it first — and IG's update suggests retail participation has cooled meaningfully. The downgrade also follows September's announcement of significant job cuts, a sign management saw this coming and is already tightening its belt.

There is a silver lining buried in the statement: first trades were up more than 25% and active customers grew around 17%, so the client franchise is still expanding — the problem is monetization, not user growth. CEO Breon Corcoran insisted the company remains confident in its medium-term outlook.

Related reading: Hong Kong stocks in worst day since March and more Stocks news.

What to watch

  • Whether peers Plus500 and CMC Markets confirm the same weakness in their own updates.
  • IG's cost-cutting progress — September's reorganisation needs to show results.
  • Market volatility: a pickup in trading activity is the fastest cure for the revenue shortfall.

MarketRadar take

The market doesn't forgive guidance cuts, especially after a "sanguine" outlook. But the 27% plunge prices in a lot of bad news while customer growth stays strong — this looks like a monetization problem, not a broken business. Bearish for IG and broker stocks near term; the sector needs volatility to return before sentiment turns.