1. CPI Card Group

Year-to-date gain: 327.79 percent; current share price: US$18.78

With customers located across the US, CPI Card Group (NASDAQ:PMTS) provides its user base with both physical and digital payment solutions, including credit, debit and prepaid options.

The company's third quarter results show that its net income rose 14 percent year-on-year to reach US$6.6 million, while net sales rose 20 percent to hit US$99.6 million. CPI said it is responding to strong customer demand by making investments in labor and equipment, with the goal of increasing its capacity and adding more capabilities. Shares of CPI reached their peak for the year on September 14 at US$38.70.

2. Atlanticus Holdings

Year-to-date gain: 175.72 percent; current share price: US$68

With a focus on everyday consumers, Atlanticus Holdings (NASDAQ:ATLC) provides lenders with technology and proprietary data analytics so they can offer more inclusive financial services. The company's bank partners use its products to set up consumer loan products like retail and healthcare credit and general-purpose credit cards.

Atlanticus also has a subsidiary that works with automotive dealers and non-prime automotive finance organizations, giving them access to financing and servicing programs.

The company's share price hit its highest level this year on November 3, coming to US$87.34. The move came two days after Atlanticus topped Fortune’s annual list of the 100 fastest-growing companies. The firm's latest quarterly results show net income attributable to common shareholders of US$40.3 million.

3. Performant Financial

Year-to-date gain: 159.93 percent; current share price: US$2.29

Performant Financial (NASDAQ:PFMT) is focused on the healthcare payment integrity industry, using technology to provide audit, recovery and analytics services. The company works with government and commercial clients in the US, and uses its proprietary platform to help them reduce losses by identifying improper payments.

Shares of Performant reached a 2021 high point of US$5.03 on August 9, the day before it shared its Q2 results. The company's third quarter results came out in early November, and they include a net loss of about US$1.7 million, slightly less than its US$2 million loss in the year-ago period. Performant said that delays impacting the healthcare space have had a trickle-down impact on its operations.

4. GreenSky

Year-to-date gain: 148.27 percent; current share price: US$11.50

GreenSky (NASDAQ:GSKY) uses its proprietary technology platform to provide point-of-sale solutions for merchants, consumers and banks. Companies that use GreenSky's "apply and buy" platform can offer their customers the option of completing purchases by borrowing money from GreenSky via a loan agreement.

Goldman Sachs (NYSE:GS) announced plans to acquire GreenSky on September 15, saying the transaction would be closing in the fourth quarter of 2021 or the first quarter of 2022. The company's share price spiked to US$11.90 that day, although GreenSky's 2021 high didn't come until November 2, when it hit US$12.54.

5. PFSweb

Year-to-date gain: 93.46 percent; current share price: US$13

PFSweb (NASDAQ:PFSW), operating as PFS, provides technologies to companies in various industries, from fashion and apparel to consumer packaged goods, helping them offer their customers ecommerce services. Among other products, PFS offers customized pick/pack/ship services and an order management platform.

PFS said on August 9 that it would be delaying the filing of its Q2 Form 10-Q with the US Securities and Exchange Commission, saying that it needed more time to meet reporting and accounting requirements for the proposed divestiture of its LiveArea business. Its Q3 Form 10-Q filing has also been delayed, and the NASDAQ has said both must be completed by February 7, 2022. Company shares hit a 2021 high point of US$13.83 on November 11.