(Bloomberg) -- Adyen NV’s shares plunged as aggressive competition in North America contributed to the slowest revenue growth since its initial public offering, erasing more than €18 billion ($19.6 billion) of market value in a single day.

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Shares of the Dutch payment processing company fell a record 40.6% to €875 at 4:49 p.m. in Amsterdam, the lowest since May 2020. Trading was temporarily halted due to volatility multiple times in the day.

Pricing competition, higher inflation and interest rates stunted revenue growth in the first half, the Amsterdam-based fintech firm said on Thursday. Net sales rose 21% to €739.1 million in the period, compared to an estimate of €776.5 million in a Bloomberg survey of analysts.

Adyen has been a reliable growth stock, with revenue rising by at least 26% in every half since its listing in 2018 until the latest period. The disappointing results, which were also hurt by inflation and rising interest rates, suggest maintaining such momentum will be a challenge.

Revenue growth in North America, which accounted for a quarter of the company’s sales in the period, more than halved to 23%. Adyen’s digital customers have been focusing on profitability more so than on growth in the US, Chief Financial Officer Ethan Tandowsky said in a phone interview.

“That did have some impact on the growth that we saw,” he said. “In a market like this, some customers choose to see if they can find a lower cost provider who could offer the similar functionality.”

It “will be difficult for Adyen to accelerate growth” in the second half as competition and currency headwinds will remain a factor, Jefferies analyst Hannes Leitner said in a note.