Fears about the COVID-19 outbreak led the Standard & Poor’s 500 Index into a correction (a drop of 10% or more from a recent high) in just six days, the fastest time to a correction from an all-time high ever. However, a few days afterward, stocks rallied, with the S&P 500—which recovered more than 40% of its losses from its February 19 close to its midday low on February 28—and other indexes notching record point gains. Since then, stocks have been extremely volatile.

When markets fluctuate, sticking to the plan you’ve laid out becomes more important than ever.

We’ve been here before

Market downturns and bouts of volatility aren’t rare events—even those that grow out of health crises such as the SARS (severe acute respiratory syndrome) outbreak in 2003 and the Zika virus outbreak in 2016. The key to getting through such turbulent times is to understand that these market conditions don’t last forever (see the figure below) and that markets can recover more quickly than you might think.

A health crisis downturn doesn’t last forever