What happened The stock market experienced its worst day in several years on Monday, with the Dow Jones Industrial Average and S&P 500 closing more than 7% lower. Many stocks did even worse, especially in the financial sector, which was the second-worst performer in the market. Only energy stocks (oil triggered today's fall) had a worse day. Specialty insurer Markel (NYSE: MKL) was no exception, finishing the day 10% lower. Image source: Getty Images. So what For starters, insurance stocks across the board had a rough day. For example, American International Group (NYSE: AIG) fell 13% and Prudential (NYSE: PRU) dropped by 17% to name a couple. By comparison, Markel actually got off easy. One major catalyst is interest rates. To say that Treasury yields "fell" would be a massive understatement. The 10-year Treasury yield fell to an all-time low of less than 0.5% -- that's about one-fourth of what it was yielding just a few months ago. Insurance companies rely on investment income to produce profits, and most invest in fixed-income securities. Markel, on the other hand, has a considerable portfolio of common stocks as well, which is why it often gets the nickname of "baby Berkshire," for its business model similarities to Warren Buffett-led Berkshire Hathaway. After today's market action, it's fair to assume that most of Markel's stock holdings have fallen. Now what There's no way to know whether this will be a short-lived market plunge or whether it will be a drawn-out bear market. However, Markel remains a well-run insurance business with a unique investment approach, and long-term investors should be just fine. 10 stocks we like better than MarkelWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Markel wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of December 1, 2019 Matthew Frankel, CFP owns shares of Berkshire Hathaway (B shares) and Markel. The Motley Fool owns shares of and recommends Berkshire Hathaway (B shares) and Markel and recommends the following options: long January 2021 $200 calls on Berkshire Hathaway (B shares), short January 2021 $200 puts on Berkshire Hathaway (B shares), and short March 2020 $225 calls on Berkshire Hathaway (B shares). The Motley Fool has a disclosure policy.Source