Global remittance and money-transferring business Remitly saw its stock price fall more than 2% this week after short seller Spruce Point Capital Management published a short report listing a litany of allegations against the $4 billion Nasdaq-listed fintech.

According to Spruce Point’s report, Remitly’s customer testimonials are “dubious” and play a significant role in its thesis questioning the company’s trustworthiness. The hedge fund claims a reverse image search tool revealed reviews that included images of smiling women wearing traditional saris and head coverings were actually just stock photos. Spruce Point also accused Remitly of manipulating the review ratings on its website. Overall, the hedge fund said these points are evidence Remitly isn’t being transparent with customers. It took a short position in the company’s stock and owns derivative securities that will benefit if the share price tumbles.

Remitly did not respond to requests for comment.

Remittance businesses are a crucial financial lifeline for low- and middle-income countries: Emigrants use remittances to send money to their home countries for bills, food, and education costs. The World Bank projects the total amount of money transferred around the globe will swell to $690 billion this year. The top five countries for remittance inflows are India, Mexico, China, and the Philippines, respectively, with the U.S. being the largest source around the world, followed by Saudi Arabia and Switzerland.

Banks are the most expensive way to send remittances, with fees about 12% of the amount, while sending money through the mobile operators costs 4.4%, according to World Bank data.

Remitly describes itself as a trusted provider of digital financial services that transcend borders and has a global footprint across 170 countries. It operates 5,100 remittance corridors around the world and users can send funds to 5 billion bank accounts and mobile wallets. It also has 470,000 cash pick-up options. CEO Matt Oppenheimer told Fortune last year that trust is key to providing services to a broad user base that counts low-income migrants sending savings to families back home. Oppenheimer said he personally handles customer-service calls when he visits Remitly call centers to ensure users are being treated with care.