In an article for MarketWatch, Mike Murphy covered a recent report that state and federal regulators are examining unusual trading patterns behind the recent volatility in bank stocks. Notably, the entire banking sector and specifically regional banks, have been subject to heightened volatility and heavy short-selling in recent months following the failures of banks like Signature Bank, First Republic, and Silicon Valley Bank.

In recent weeks, there have been big declines and large amounts of put buying in the stocks of regional banks like PacWest, Western Alliance, and Zions. The core challenge for these banks is that they made long-term loans at much lower rates, yet they have to increase short-term deposit rates or risk depositors leaving for higher rates elsewhere. And the risk of this deposit flight increases if concerns about a bank’s financial health increases.

Both the White House and the SEC noted the short-selling pressure on banks possibly contributing to the volatility. In a statement, SEC Chair Gary Gensler said, “In times of increased volatility and uncertainty, the SEC is particularly focused on identifying and prosecuting any form of misconduct that might threaten investors, capital formation or the markets more broadly.”

Finsum: With increasing volatility in the banking sector, regulators and public officials are examining short-selling and put buying as factors that may be adding to volatility.