Credit card giant Visa just agreed to spend more than $2 billion to buy the Swedish fintech company called Tink. Tink brands itself as “Europe’s leading open banking platform.”

Open banking is the sharing of your personal banking data with a third party. With your consent, an app gets to see your bank account activity. That could range from the size of your direct deposits and, said Markos Zachariadis, a fintech professor at the University of Manchester in the UK, to “the number of transactions, who did the customer transact with, how much did they paid for coffee, and so on and so forth.”

Now these third-party apps — which you may already be using — offer all sorts of things in return. Take Venmo, which allows you to send money to friends. Or a budgeting app like Mint, which will analyze your spending history. Other third party platforms, like the online lender BlueVine, are meant for small business owners. 

Sabrina Howell who teaches finance at NYU’s Stern School of Business explained: “BlueVine might want to access bank information in order to understand how risky a potential borrower is.”

Often, third party apps rely on fourth parties, companies that build the technology that lets them connect to banks. That’s what Visa’s acquisition, Tink, does.

But experts warn there can be a risk to the open banking concept. “By providing the authentication, the login information to these third parties, you know, we open ourselves up to many different avenues for hacking and security breaches,” said Howell.