The recovery at financial trading group Plus500 Ltd (LON:PLUS) continued in the first half but costs weighed.
Plus500 posted higher profits, revenue and dividends as market volatility after the UK's EU referendum boosted business.
It said underlying pre-tax earnings rose 6% to US$59.1mln on a 25% increase in revenue to US$158.8mln in the six months to the end of June.
The group increased new customers to a first-half record, which it described as substantially ahead of expectations. It also boosted its dividend by 10% to US$0.2324.
But it said the rise in clients had temporarily suppressed profit margins and average revenue per user due to acquisition and customer "onboarding" costs.
Chief executive Asaf Elimelech said: "Overall our expectations are unchanged - momentum is expected to continue, resulting in strong growth in 2016."
The company is recovering after regulatory issues caused disruption last year.
It had to stop taking on new customers in the UK after May due to regulatory concerns about anti-money laundering checks on new clients.
It said in February this year that the issues had significantly disrupted its business, but that regulatory and compliance processes related to acceptance of new clients had completed.
Shares in the group fell 2.5p, or 0.3%, to 728p in early London trading.