Bill Ackman
Bill Ackman.
  • Bill Ackman, Jeffrey Gundlach, Mohamed El-Erian and others are warning the banking turmoil is far from over.
  • Chaos has ripped through the sector for the past two months, causing four lenders to collapse so far.
  • Here are some of the most recent warnings from high-profile investors, analysts and other experts.

Over the past week, First Republic Bank became the fourth US lender to fold up this year, fueling a selloff in regional bank stocks. That's prompting top economists and investors to once again warn that the banking turmoil is far from over.