(Bloomberg) -- Charles Schwab Corp.’s worst month in more than 35 years has sparked a debate among analysts as to whether the brokerage giant has been unfairly punished by investors amid growing fears about the US banking sector.

Shares of the firm plunged 33% in March, their biggest drop since October 1987, the month when the biggest single-day stock market crash, dubbed Black Monday, occurred. The rout wiped out $47 billion in market value from Schwab, roughly equivalent to the size of Truist Financial Corp.

“There are times in markets where logic is thrown out the window and emotion takes over and I feel like this is one of those moments with Schwab,” said Adam Sarhan, founder of 50 Park Investments. 

He added that the rout is a “historic buying opportunity” for the financials sector as a whole and something not seen since 2008. Other brokerage stocks were also lower, just not as much as Schwab. Interactive Brokers Group Inc. for instance, fell about 4% in March.

Schwab is facing a pair of headwinds. Its banking arm, one of the largest in the US, is dealing with some of the same issues that plagued the now-defunct Silicon Valley Bank. Like many of it peers, Schwab invested in long-dated bonds during a period of historically low interest rates and is stuck with losses on those investments as the Federal Reserve has increased interest rates over the last year.

Read more: US Banks Have $620 Billion of Unrealized Losses on Their Books

Higher rates have also created another headache for Schwab, customers seeking better returns are moving their cash deposits into higher yielding assets like money-market funds within the brokerage or elsewhere. That process — often referred to as cash sorting — has put pressure on the company’s profit outlook. 

“As cash sorting occurs, that effectively hurts earnings power,” said JMP Securities analyst Devin Ryan. He added that Schwab is now paying well over 4% for deposits that it was once paying just about 0.5% for.

Read more: Flight to Money Funds Is Adding to the Strains on Small Banks

The pace at which customers are shifting their cash at Schwab spurred Morgan Stanley analyst Michael Cyprys to cut his rating on the stock for the first time since he began covering the brokerage company in 2016. Still, Bank of America’s Craig Siegenthaler, who downgraded Schwab in January, remains the only analyst with a sell-equivalent rating on the stock.

Schwab is set to report its first-quarter results before the open of trading on April 17. Its shares have fallen at least 1.5% during each of its last five sessions following its earnings release. 

Buying opportunities like this are very clear in hindsight, according to Sarhan. Still, “having the courage in real time is very difficult,” he said.

(Updates with closing prices.)

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