The stock market has taken a massive haircut in September. For example, the S&P 500 market index fell 3.7% from the start of the month to September 20. That might not sound too bad but the market value of these 500 high-quality companies adds up to $38.3 trillion today. Pushing this enormous pile of market value 3.7% lower will subtract a staggering $1.42 trillion from the market. That's

It's not all bad news, of course. One investor's market crash is another's buying window. September's rush to ultra-safe assets has dragged many fine investments down for no particularly compelling reason. These are the opportunities you're looking for when you want to buy great stocks on the dips.

On that note, you should take a good, hard look at these fantastic stocks that are trading at a September discount right now. All of them are poised to not just bounce back but to soar and generate shareholder wealth in the long run.

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Image source: Getty Images.

1. Newegg

Online electronics and computer parts retailer Newegg Commerce (NASDAQ:NEGG) has seen its shares fall 19% in September 2021. Market makers shrugged off an impressive guidance update, getting right back to driving Newegg's share prices lower.

I added a few Newegg shares to my own portfolio in August. Now I'm tempted to double down on that investment at a significant discount.

First, the company issued its first earnings report as a public company at the very end of August. Sales rose 40% year over year to $1.2 billion in the first half of 2021 while earnings held steady at $0.05 per diluted share.

Two weeks later, the company provided guidance for the second half of fiscal year 2021. Newegg aims for total sales of $2.4 billion this year, up from $2.1 billion in 2020. Earnings will remain positive. Newegg's shares posted a 3% gain the next day, before getting back to their regularly scheduled downward trajectory.

Here's the deal. Newegg investors see slower revenue growth in the second half and it's easy to jump to the conclusion that the company's growth engines are running out of rocket fuel. However, the second half compares to the highly unusual second half of 2020, where millions of traditional office workers were still setting up digital home offices.

Furthermore, cryptocurrencies were taking off on a fresh rocket ride in the fall of 2020. Leading smart contracts token Ethereum (CRYPTO:ETH) traded below $400 per token in October but closed the year at $730 per token. Today, the Ethereum cryptocurrency is trading at nearly $2,900 per digital token. Mining Ethereum tokens with the help of high-end graphics cards has been a highly profitable endeavor over the last year, ensuring that Newegg and other computer hardware retailers are selling those graphics cards faster than they can obtain them.

Together, the pandemic and the cryptocurrency mining craze led to fantastic financial results for Newegg in the second half of 2020. There's no shame in failing to completely crush this year-over-year comparison. What I see here is a phenomenally healthy e-commerce business with a well-oiled infrastructure. The stock is trading for a bargain-bin valuation of just 2.4 times projected annual sales, and that's a steal in my book.

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Image source: Getty Images.

2. Criteo

Digital marketing expert Criteo (NASDAQ:CRTO) has lost 11% of its market value in September, now trading 27% below June's 52-week highs. Like Newegg, Criteo really didn't do anything to earn this dramatic writedown. Therefore, astute investors should take advantage of this mispricing and pick up some Criteo shares on the cheap.

And I do mean "cheap." Investors can pick up Criteo's stock at the bargain-bin valuation of 0.9 times trailing sales or 13 times forward earnings. The company has posted revenue growth at an average annual clip of 9.4% over the last five years, including a 25% jump in August's second-quarter report. The company is solidly profitable and has beaten Wall Street's consensus earnings targets in every quarterly report since the spring of 2016.

The stock is cheap because many investors believe that Criteo's business is at risk. The company has relied for many years on so-called third-party cookies in order to track user behavior in web browsers, and that technology is going away as we speak. Most browser makers have already implemented an off-switch for third-party cookies in order to serve the privacy needs of their users. Some have even turned that tracker-stifling technology on by default, and that approach will be omnipresent in a couple of years.

However, Criteo and its peers are turning to alternative user-tracking methods. In particular, Criteo is working with its many content publishing partners to get anonymized user behavior data directly from the original source instead of relying on third-party technology hacks.

"This is our strategy: to be the centerpiece of Commerce Media for the open Internet," Criteo CEO Megan Clarken said in the second-quarter earnings call. "Once data no longer is transmitted by cookies, connected first-party supply will become the only way to provide the opportunity for both marketers and media owners to effectively advertise and monetize consumer audiences on the open Internet, and this is exactly where we're going."

In other words, Criteo's business is running smoothly today and should continue to do so when the cookie trackers go away. Market makers are still acting as if the shift away from third-party cookies is the end of the world for Criteo. It really isn't, and that's why the stock is a solid buy at today's modest prices.

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.