Bank earnings are back in focus.

This week, several major U.S. banks are set to report results, giving markets a fresh look at the health of the financial sector and the broader economy.

The key focus is not only on headline earnings. Investors will also be watching lending activity, consumer demand, deal flow, credit quality and management outlooks.

These reports can influence market sentiment well beyond the banking sector, especially when they change expectations around growth, risk and future financial conditions.

Four major banks. One important market signal.