Will the stock market crash again? Absolutely yes. It's a matter of when not if. 

There are plenty of investors who expect that when to be sooner rather than later. We're already seeing increased market volatility as the number of COVID-19 cases in the U.S. rise. The prospect of a severe second wave of outbreaks in the fall could be enough to pop what some think is a stock market bubble.

I don't want the stock market to plunge again anytime soon. But I'll readily admit that a part of me wouldn't mind the opportunity to scoop up shares of several of my favorite growth stocks at a lower price. Here are three stocks that I absolutely, positively will buy if the stock market crashes again.

Businessman holding pin close to a bubble with a rising stock chart in it

Image source: Getty Images.

1. Fastly

Since its low point on March 16 in the last major stock market downturn, Fastly (NYSE:FSLY) has delivered a staggering gain of more than 680%. I bought the stock a few weeks ago, too late to get in on most of the wild ride but soon enough to still enjoy a substantial return in a short period of time.

Fastly has been such a huge winner because it's an ideal COVID-19 play. The company's edge computing and content delivery network (CDN) platforms speed up the delivery of apps and data from the cloud, which is increasingly important with companies allowing employees to work from home like never before.

Shares currently trade at more than 33 times sales with a market cap approaching $8 billion. That's admittedly a nosebleed valuation. I don't think it's too late to buy Fastly, though: The company's addressable market is projected to be around $36 billion by 2022, giving Fastly plenty of room to run.

I'd love to have an opportunity to increase my position in Fastly if it pulls back in an overall stock market decline. But I doubt I'll wait to see if it happen. Fastly's prospects are so tantalizing that I'll likely buy more shares regardless of what the stock market does.

2. Livongo Health

Shares of Livongo Health (NASDAQ:LVGO) have skyrocketed more than 270% since bottoming out in mid-March. I didn't buy the stock until early May, but it's still generated a hefty gain over the last couple of months.

Livongo is another company that has benefited from the COVID-19 pandemic. The company specializes in providing technology that helps people better managed their chronic conditions. Remote monitoring and disease management for individuals with diabetes and hypertension have taken center stage and will likely grow in importance even after the pandemic is over.

A price-to-sales (P/S) ratio of more than 36 would be scary for most investors. It would be for me, too, if I wasn't confident about Livongo's growth potential. The company estimates that its addressable market is close to $47 billion. But that total only includes the U.S. market and only diabetes and hypertension. Livongo is also targeting other chronic conditions such as behavioral health issues and could expand into international markets down the road.

Still, it would be great to buy more shares of Livongo Health on a dip or dive. My view is Livongo, like Fastly, should be more resilient than most stocks if the COVID-19 pandemic worsens. But it could still pull back somewhat. If it does, I'll be ready to pounce.

3. The Trade Desk

The Trade Desk (NASDAQ:TTD) stock has soared more than 56% year to date and is up more than 180% since its low on March 18. I'm glad to say that I've owned the stock for a while and participated in all of the fun experienced in 2020 so far.

The COVID-19 outbreak presents a risk for The Trade Desk. The company's programmatic advertising platform makes money when ad agencies buy ads. If those agencies' customers cut back on their advertising budgets, The Trade Desk suffers. That's what happened in March, but it was only a brief headwind: The company's sales bounced back quickly.

Yes, The Trade Desk's shares trade at a premium with a P/S ratio of 27. However, the meteoric rise of connected TV (CTV) is fueling rapid growth in programmatic advertising. Over the next decade, I fully expect a big slice of the projected $1 trillion-plus global advertising market will be programmatic -- with The Trade Desk a prime beneficiary.

If another stock market crash happens in the near future, it will likely be because of fears about a second wave of the coronavirus outbreak or a prolonged recession resulting from the pandemic. Either scenario could cause The Trade Desk stock to falter, especially if advertisers reign in spending. My view, though, is that would be only a temporary problem that would present a terrific opportunity to buy The Trade Desk on the cheap.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.