What happened

The massive coronavirus-fueled downturn in the stock market continued on Thursday, with the Dow Jones Industrial Average and benchmark S&P 500 index down by 9% and 8%, respectively, by 2:45 p.m. EDT.

Financial sector stocks were hit worse than most. To name a few, wealth manager Affiliated Managers Group (AMG 0.11%) is down by 15%, regional bank Western Alliance Bancorp (WAL 0.14%) has dropped by 12%, insurance giant Aflac (AFL -0.43%) is off by 13%, and specialty insurer Markel (MKL 0.31%) is more than 12% lower on the day.

Businessman watching red arrow crash through the floor.

Image source: Getty Images.

So what

There are a few reasons financial companies are getting hit especially hard. Plunging interest rates affect banks and insurance companies alike. Banks make much of their money by earning interest on loans, and insurance companies generally invest in high-grade bonds. Lower rates are bad for both.

On the insurance side, there's also the possibility of more claims as a result of the virus itself. And on the bank stock side of the financial sector, there's the prospect of a sustained economic downturn, which would hurt demand for loans and would also likely increase default rates on existing loan products.

Now what

The market downturn is still a volatile situation, and there's simply no way of knowing if there's more room to the downside or if the market will rebound quickly if virus fears subside. However, it's fairly certain that the profitability of banks and insurance companies could take a serious hit for the first half of 2020 -- it's just a question of how bad and long-lasting the damage will be.