When it comes to the stock market, there are a lot of things that can spook it. You may have heard of the “October Effect.” Or the “September Slump” that precedes it. Both market theories refer to historical patterns of scary market declines during these months. And over time they’ve fueled fears that stock prices are destined to plunge.

The reality is that stock returns actually rose in 54 Octobers vs. 39 Octobers when they fell, according to historical data from Yardeni Research, Inc. Even so, market turmoil — whether it’s tied to the time of year, a world event or the latest meme stock — can be unnerving. It sparks questions and uncertainty about investing wisely. And it keeps some investors on the sidelines.

How should we respond to inevitable market ups and downs — or should we? Here are some essential things to know about volatility and a few tried-and-true suggestions for dealing with it.

What is market volatility?

Without getting too deep in the weeds, volatility is simply a measure of how much stock market values move. When volatility is low, stocks trend in a stable way. When volatility is high, stocks fluctuate rapidly in a short time frame.

Volatility generally comes in cycles, although many triggers — like inflation, Federal Reserve actions or a pandemic — can deliver a hard swing. Generally, though, periods of high volatility give way to periods of low volatility and vice versa.

Coping with volatility isn’t easy. The stock market can be unpredictable, so it’s wise to focus on aspects of investing that you can control versus those you can’t. Here are three things to keep in mind.

Put market moves in perspective

Passionate headlines about bull and bear markets can stoke feelings of stress and uncertainty. It may not seem like it when stocks are in freefall and worry runs high, but historically the market’s upside movement has tended to prevail over declines long term.

For instance, the Schwab Center for Financial Research looked at both bull and bear markets for the S&P 500 Index going all the way back to the late 1960s and found that the average bull market lasted about six years, producing an average cumulative return of over 200%. The average bear market lasted a little under a year and a half, delivering an average cumulative loss of 39%.

Embrace diversification

How can you help cushion the blow of volatility? By not putting all your eggs in one investment basket. Spreading money across different types of investments is important because each can respond to the market differently. When one is up, another may be down.

Diversifying your investments — divvying up the allocation among stocks, bonds and cash — creates a built-in buffer against risk. And once you figure a target variety, checking it periodically and adjusting if it veers off track will help maintain your optimal mix.

Hang tough

It’s tempting to take action when the market tanks. But emotion-driven reactions don’t always serve investors well. Consider this: A leading study of investor behavior by financial research firm DALBAR found that only 11% of investors cashed out investments in response to the market crash last March, at the start of the pandemic. Keeping cool under pressure helped those who stayed in the market outperform the S&P 500 in six of the last eight months of 2020.

The takeaway? Sometimes, no action is the best action. Bailing out of stocks as prices fall in an attempt to stem losses could end up turning “paper” losses into much more frightening real ones. What’s more, wait for the “right” time to jump back in, and you may miss out on gains when stocks rebound.

Staying the course

October has a bad reputation for stock market crashes. But in many cases, you shouldn’t let it scare you into drastic steps. Nevertheless, it’s always important to be honest about how much risk you’re comfortable with. Then, use that tolerance level to help guide investing decisions (and let you sleep at night). Likewise, if goals or life events change, you may need to reset and reshuffle your portfolio. But regardless of which month it is, keeping your focus on the future just might be among the least spooky moves to make.