American depositary receipts (ADRs) of Dutch payments giant Adyen (ADYEY) plunged more than 35% in midday trading Thursday after the company reported its slowest sales growth ever, citing competition in key markets including the U.S.

Adyen's net revenue of 739.1 million euros ($805 million) for the first half was 21% higher than the same period a year ago, but still came in below analysts' estimates. Processing volumes were up 23%, but earnings before interest, taxes,𝐆 depreciation, and amortizatꦬion (EBITDA) were down 10% year-over-year.

T🦩he company said higher costs from hiring more employees, wage growth, stiff competition from other payments firms, and a shift in spending by American business clients impacted its results. Adyen also cited headwinds from higher prices and and interest rates as impacting its U.S. businesses.

Adyen hired 551 employees in the first half of 2023, after 1,150 new full-time employees were added in 2022. That raised costs, though Adyen noted it was "unable to hire enough top-quality talent" to keep up with its plans in the U.S., adding, "We now see the impact of a sales team size that did not match our ambitions, particularly in North America. Since then, we have ramped up our investments."

Thursday's decline put ADRs of Adyen into negative territory for the year.