• Hong Kong-listed shares of China's big four banks were mixed even though all of them reported higher profits and wider margins last week.
• Investors fear that Chinese authorities, facing a slowing economy and worsening tensions with the U.S., may abandon plans to deleverage and the banking industry could see bad debt pile up again.

The latest earnings reports from China's big four banks showed improvements across key financial metrics, but some investors remain worried that things could get worse for lenders in the world's second-largest economy.

Such concerns arose after the country's central bank, the People's Bank of China, made several moves to loosen monetary conditionsas economic growth slows and as trade tensions with the U.S.worsen. That made investors fear that Chinese authorities may abandon plans to reduce harmful debt in the economy, which could hurt the banking industry.