Worries about the Wuhan coronavirus are hitting global stock markets hard, and that's been especially troubling to investors who've largely seen stock prices move nearly straight up over the past decade. With so many people on Wall Street having worried about when the long bull market in stocks would come to an end, it's natural to be afraid of what could come next -- especially if you're thinking about putting new money to work in the market right now.

Nobody wants to look silly by investing when stocks are at their most expensive. But market downturns are a fact of life, and they're the price you pay to get the long-term returns that stocks offer investors who go the distance. You have to learn to live with them, and while they're not always comfortable, they can actually help you improve your overall performance -- if you're prepared and know what to do.

Following are four things to think about right now, before a big downturn strikes.

1. Be honest about your emotions

The best investors are able to keep their emotions in check and think rationally even during tough times. But not all of us have that kind of discipline. When we're watching the savings that we've worked so hard to set aside suddenly evaporate in a falling market, it hurts -- and we want to stop the hurt by selling our stocks and at least preserving whatever's left.

Graph with red line going down, next to picture of Alexander Hamilton.

Image source: Getty Images.

It's true that if you did that, you'd avoid the worst losses in a true bear market. But if you sell at the first sign of a possible downturn, you'd also miss out on all the times when the market abruptly bounces back. That happens a lot, and when it does, you'll want to buy back at a higher price to avoid missing out on further gains.

The best thing to do before a big downturn hits is to look at your risk tolerance honestly. It's easy to answer a questionnaire saying you wouldn't mind losing 20% of your portfolio, but when you see thousands or tens of thousands of dollars disappear all at once, it can be another thing entirely. Experience will be your best teacher, and if you've ever been through a downturn before, think about how you felt and prepare to deal with the same emotions again.

2. Think about rebalancing

The best thing to do during the bull market of the past 10-plus years has been to let your gains ride. But as stock prices go up, so too does your overall risk level in your portfolio. That in turn leaves you more exposed to future market crashes.

Rebalancing your portfolio, on the other hand, essentially locks in a portion of your profits while still giving you a reasonable amount of investing exposure and potential returns consistent with your risk tolerance. Rebalancing is a good middle-ground between doing nothing and panic-selling, and it'll help reduce your losses if a crash does happen.

3. Get your buy list ready

Have you complained about never being able to buy the stocks you want at the price you'd like to pay? A market crash can be your best chance to get your favorite stocks on the cheap.

It can be a lot harder to pull the trigger on a stock purchase in the midst of a crash than you'd think, though. Once again, emotions can get in the way and make you hesitate too long. But if you make a plan beforehand, then you might catch yourself actually being happy about a market downturn -- and the stocks you purchase while prices offer good value can give you some of your best results.

4. Keep it automatic

One strategy that a lot of people use is to pay themselves first by investing set amounts each month. Brokerage companies and other financial institutions love this, because it keeps money flowing you're your account. It can also be helpful to keep you on track no matter what the market does.

Staying on autopilot works especially well when markets tumble, because the amount you invest can purchase more shares. When the market bounces, those extra shares add to your overall returns -- leaving you far better off than you would've been if you'd put your investing on hold.

Be greedy when others are fearful

There's no way to stop the market from falling sometimes. If you're ready with the right strategy, though, you can capitalize on falling markets -- and maybe even get to the point where you look forward to the next time you'll get a chance to invest in stocks at  bargain prices.