The coronavirus pandemic and the related economic shutdown may be devastating for the American economy at large, but Wall Street trading desks have raked it in amid one of the most volatile periods in the stock market’s history.

Trading revenues at the “big five” U.S. banks—Bank of America, Citigroup, Goldman Sachs, JPMorgan Chase, and Morgan Stanley—swelled 30% in the first quarter of the year on the back of a market correction that resulted in “a spike in volatility,” Fitch Ratings said in a report Monday.

As the pandemic sent the stock market into historic, topsy-turvy fluctuations last month, investors desperately sought to move their money around and traders were more than happy to assist them—with the market’s wild swings proving an opportunity for some.

Overall, capital markets results at the five major banks grew 23% in the first quarter—hitting their strongest level in nearly a decade, per Fitch—thanks not only to heightened trading activity, but also an uptick in debt issuances by companies seeking liquidity to ride out the economic shutdown.

Goldman Sachs experienced its strongest fixed income, currencies and commodities (FICC) trading revenues in five years, while Bank of America registered its best-ever equities trading results and JPMorgan saw record debt underwriting revenues, the ratings agency noted.

But while the increase in client activity is proving a boon for banks at the moment, lower interest rates and declining economic activity “could prove to be a headwind for banks later this year,” according to Fitch managing director Christopher Wolfe. Activity on the IPO underwriting and mergers and acquisitions fronts also came to a relative standstill in March, and will likely remain a challenge in the months to come.

As such, Fitch—which revised its ratings outlook for the U.S. banking sector to negative last month—reiterated that “most U.S. banks will face meaningful profitability challenges” in the near future, with the drop in interest rates hampering spread revenues “for a number of quarters.” Fee income will also be hurt as corporate and institutional clients continue to pull back from the market.

Those dynamics explain why bank stocks—like financial sector stocks at large—have taken a pounding this year as the economic impact of coronavirus pandemic became apparent. The five major banks cited by Fitch have lost anywhere from 21% to 45% of their market value this year to date, while the S&P 500’s financials sector is down 29% in 2020 so far.