Square lost its CFO and its stock price slid. Sarah Friar, Walmart board member and Chief Financial Officer of Square, Inc. listens at the Walmart annual formal business and shareholders meeting on May 30, 2018 in Rogers, Arkansas. Rick T. Wilking/Getty Images

Square, Inc. (SQ) had nothing but positive momentum on the stock market for the past year, but Wednesday and Thursday took the firm’s share price in the opposite direction. The payment services company took a significant hit after it announced on Wednesday that CFO Sarah Friar would leave the company.

After six years at Square, Friar will be the new CEO of neighborhood-based social network Nextdoor. She oversaw Square’s business operations when the company went public in 2015. Square ended Wednesday down more than 10 percent and did not fare any better on Thursday. In the hours after markets opened, Square’s share price dropped by more than 14 percent at one point.

“It is rare to work at a company that aligns such a meaningful purpose with unbounded market opportunity,” Friar said, per Square’s press release. “It has been a privilege to work with such a talented executive team, who pushed me and the company to move further and faster every day.”

Square CEO Jack Dorsey, who also Twitter’s CEO, called Friar a “multidimensional leader” and congratulated her on getting to run her own company in a note he shared on Twitter. She will replace Nirav Tolia at Nextdoor. The outgoing CEO announced his departure over the summer.

Square’s midweek stock market slide came after a year of enthusiasm over the financial management firm. The company’s diverse line of both consumer and enterprise products played a role in the stock’s rise of over 105 percent this year. Even after Wednesday and Thursday’s losses, Square’s stock price is still comfortably higher than its $9 IPO price.

The firm was founded in 2009 and rose to prominence with its square-shaped mobile credit card readers that are widely used by businesses. Square also runs Cash App, a Venmo competitor for online money transfers. Cash App’s download count exceeds Venmo, according to Motley Fool.

Square actually had one of its best stock market days ever on Sept. 25, following the launch of its Square Payroll app. The new mobile app allows employers to manage payroll from their phones.