Investors have long debated the relationship between growth and value. In 2022, value stocks have shown better results: The iShares S&P 500 Value ETF is down 9.5% this year, while the iShares S&P 500 Growth ETF is down by 31.7%.

But growth tends to outpace value in the long run. A $5,000 investment in that iShares Growth exchange-traded fund 10 years ago would be worth $17,620 today, as long as you reinvested your dividends along the way in more units of that ETF. The same investment in the Value ETF would be worth only $14,040.

Chart showing overall growth trend in the iShares Growth, Core S&P 500, and Value ETFs since 2014.

IVW Total Return Level data by YCharts

The stock market rises and falls in multi-year cycles. If the current trend toward value stocks turns into a renewed appreciation of growth stocks, long-term investors who build large positions in top-quality growth stocks will be well rewarded. So which growth stocks are worth buying right now? Let's take a look at two growth-oriented names that can lead the way to wealth-building gains in the long run.

Duolingo would like to teach the world to sing (in Spanish and Greek)

Let's start with a personal favorite. So far, online learning expert Duolingo (DUOL -0.55%) is known for its language courses. That operation works quite well, judging by Duolingo's just-released third-quarter results.

The company exceeded analysts' targets on both the top and bottom lines. Sales increased by 51% year over year, and net losses per share were nearly cut in half.

More to the point, all user metrics are moving in the right direction. Duolingo saw the number of monthly active users (MAUs) rise 35% to 56.5 million. These users are also more engaged than ever, as daily active users (DAUs) rose even faster at a 51% clip. 14.9 million people interact with Duolingo every day.

But wait -- there's more! Duolingo's paid subscribers soared 68% higher, landing at 3.7 million names. These people have graduated beyond the free service and are willing to pay Duolingo for a smoother, ad-free learning experience with extra features.

Those are the user engagement trends I want to see in any stock tied to a freemium business model.

Chart showing a growing trend in subscription sales among Duolingo's monthly active users since 2020.

Image source: Duolingo.

And that is only the start of a grand long-term ambition. Every earnings release starts with a full-page presentation of the company's mission statement: "Our mission is to develop the best education in the world and make it universally available."

That statement doesn't even mention language learning. This company was always meant to start with this relatively simple subject and then branch out into other fields of study. Duolingo's smartphone-based learning platform packages lessons with a friendly collection of cartoonish characters, led by the green owl, Duo.

Game-like features motivate users to do more than the bare minimum, boosting the app's educational efficiency and its fun factor. Doing both at the same time, based on the same trick, is a rare accomplishment. These people know what they are doing.

Duolingo's share price has fallen 43% over the last 52 weeks, setting the stock up for a powerful rebound once the market gets over its current fear of high-growth names. Excuse me for a minute -- there's a 2,331-day learning streak to extend and some new French phrases to learn, or maybe a couple of Japanese kanji characters.

I'll be right back!

The Trade Desk swims against the stream in troubled waters

Merci beaucoup pour la pause! Next, let's take a look at a superstar of digital advertising.

You may have heard that the online advertising market is experiencing a brutal slump right now. Ad-based revenue streams are drying up as the largest ad buyers slam the brakes on their marketing budgets. That's one side effect of the 2022 inflation crisis.

The Trade Desk (TTD -2.95%) didn't get that memo. At a time when other businesses with close ties to digital ad sales are reporting slower revenue growth, The Trade Desk's top line is racing ahead:

Chart showing plateauing in the online ad revenue of several major tech companies, with The Trade Desk outperforming.

TTD Revenue (TTM) data by YCharts

That trend remained in Wednesday's third-quarter report. The marketing campaign organizer's year-over-year revenue growth came in at 31%, only slightly below 35% in the second quarter and 43% in the report before that. Meanwhile, the top-line growth of the sector peers in the chart above slowed down from 20% or more to a single-digit crawl or actual shrinkage.

The Trade Desk achieved this feat because its services help clients get more value for each dollar spent on ad campaigns. The better this company is at its job, the more efficient digital marketing campaigns become. As a result, the Trade Desk's services keep more money in the pockets of ad buyers and less in the outstretched hands of advertising platform operators.

The Trade Desk can thrive in times of economic pressure and tight budgeting belts. That doesn't stop the company from doing well when the ad market is booming. Year-over-year sales growth has not been lower than 24% at any point in the last two years.

But, despite The Trade Desk's formidable business results, the stock has fallen 46% over the last 52 weeks. This company is going places in the long run, and the stock is poised for tremendous gains from this rock-bottom starting price.