All it took was a few tough words from Credit Suisse Group AG’s biggest shareholder on Wednesday to spark a selloff that quickly spread across global markets.

In response to a question about whether Saudi National Bank was open to further cash injections, Chairman Ammar Al Khudairy said “absolutely not.” It was a reminder about the precarious situation facing the Swiss bank, and another reason for investors, still nervous after the collapse of Silicon Valley Bank, to sell.

Management has sought to bolster confidence this week about the bank’s turnaround plans. Chief Executive Officer Ulrich Koerner said on Tuesday that business is starting to improve and Chairman Axel Lehmann said government assistance “isn’t a topic.”

Still, it wasn’t enough to stop investors from fleeing. Credit Suisse’s share price plunged 28% in the biggest one-day selloff on record, leaving it down more than 75% over the past year. The firm’s bonds fell to levels that signal deep financial distress, with securities due in 2026 dropping 17.75 cents to 70 cents on the dollar in New York. That puts their yield at about 20 percentage points above US Treasuries, according to Trace.

“Markets are very sensitive to the negative news flow after the surprise of seeing a US bank disappear from one day to the other,” said Francois Lavier, head of financial debt strategies at Lazard Freres Gestion. “In a context where market sentiment is already weakened, not much is needed to weaken it even further.”

The panic selling in Credit Suisse spread around the world, hitting European banks and dragging US stock markets lower. Two-year yields on German yields fell 50 basis points to below 2.5% in a flight to safety.

Societe Generale SA and BNP Paribas SA fell more than 10%. The combined market value lost among European banks was more than $60 billion on Wednesday.

Credit Suisse is just months into a complex turnaround plan that will see the Swiss firm spin out the investment banking unit while focusing on its key wealth management business. That effort risks being further complicated by market unease across financials after the collapse of multiple US regional banks.

A spokesperson at the bank declined to comment when contacted by Bloomberg News. 

“When we have this kind of material risk, it takes some time for calm to come back to markets,” said Frederic Dodard, head of asset allocation at State Street Global Advisors Ltd. “We could continue to see market swings for a few days, especially with central banks meetings this week and next week. They could help restore confidence or even worsen it. We’re not out of the woods yet.”

--With assistance from Macarena Muñoz and Chiara Remondini.

This article was provided by Bloomberg News.