Aquis said it made an operating loss of 200,000 pounds ($249,500) in 2019, down 93% from 2018.

Market share in pan-European stocks trading rose to 4.6% from 3.8%, and it ended the year with 11 million pounds in cash and no debt, it said.

Aquis shares were up 6% at 362 pence at 1005 GMT,

Chief Executive Alasdair Haynes said the company will invest a million pounds in hiring more technology staff this year and therefore won't be profitable until 2021.

"We have to make a significant investment to gain more in the long term and that went down pretty well in the market," Haynes said.

Aquis competes with pan-European exchanges like Cboe, which has a market share of around 20%, and the London Stock Exchange's Turquoise platform.

It added three clients to reach 30 in 2019, a slower rate of increase than expected, with Haynes citing uncertainty over Britain's departure from the European Union and its impact on cross-border share trading.

"We were expecting to see substantial growth in clients this year but the coronavirus could cause a slowdown," Haynes said.

Many trading houses are having to work off-site or from home, with the lockdown in Britain expected to last until May at least, making it harder to physically connect new customers.

The total number of clients is likely to hit 40 during 2020 out of a pool of 80 to 100 potential clients.

Haynes said he was sticking with a market share target of 10%, though declined to give a target deadline.

"It's going to take some time. We will reach 10%," Haynes said.

Broker Liberum said the 2019 results were ahead of expectations. "We note the significant increase in value traded on the exchange in February and March. This will lead to clients trading more and entering higher revenue tiers," it said.

Five EU countries renewed their bans on short-selling of shares on Wednesday, with Italy already having extended its ban.

"It's a case of damned if you do and damned if you don't," Haynes said.

The bans have divided regulators with Britain and Germany not following suit, and triggered opposition from hedge funds and high-frequency traders (HFT) that favour short-selling strategies.

"You cannot have companies go bust due to exceptional circumstances," Haynes said.

Aquis does not allow HFT firms on its market and volumes dipped in March when they hit record levels at other exchanges.

By Huw Jones