baindigital14More than 2,000 years ago, in honor of the Chinese Lunar New Year, elders in China began giving coins threaded with red string, to ward off evil spirits. Red envelopes, or hongbao, stuffed with paper money later replaced the coins, and the practice spread throughout Asia.

The tradition continues today, but with a modern twist. On the most recent Lunar New Year’s Eve, users of the mobile messaging app WeChat sent their money-stuffed red envelopes—1 billion of them—to family and friends electronically, on their mobile devices.

Sending e-hongbao is a big sign of changing times in the banking world, but there are smaller but equally significant signs. I’ve been reading Bain’s Customer Behavior and Loyalty in Retail Banking Report, and one of the more striking conclusions from the 115,000-person survey: People are more likely to miss their phones than their wallets.

Think about the times you’ve forgotten your wallet at home. Maybe you had to borrow money from a coworker or stop home before grabbing dinner with a friend after work.

Now think about the times you’ve been separated from your phone. If you’re like me, your phone has become a critical tool for managing your life, from your calendar to your banking apps and contacts. Who remembers phone numbers anymore? Just thinking about forgetting my phone makes me nervous.

Phones have become the hubs of personal finance for most people. That’s why the savviest banks are investing heavily in their mobile apps. Bain’s survey suggests that mobile apps are much more likely to delight consumers and earn their loyalty than traditional banking services built around physical branches.

The trend toward mobile seems like a no-brainer for banks, but there is one big catch: Banks now face competition not only from other banks, but also from newcomers like Apple, Google and Square.

Few of these disrupters have made as big a splash as China’s WeChat, which started as a messaging app and now offers a tantalizing preview of what Silicon Valley–based banking apps could accomplish in the near future.

In addition to sending and receiving virtual red envelopes, WeChat’s more than 600 million active users use the app to buy goods, pay bills, send money to family and friends, move funds between investment and savings accounts, and even book travel. The ability to do all that and more without manually typing large strings of numbers from a plastic card helps explain why a staggering 80% of consumers in China and South Korea would rather lose their wallets than their phones.

While the trend toward mobile banking is clear and growing, banks’ infrastructure and security systems give them an edge over social networks that are merely dabbling in personal finance. But who knows how long that advantage will last in a rapidly digitizing world?

You can check out Bain’s Customer Behavior and Loyalty in Retail Banking Report here.