After watching growth stocks get pummeled mercilessly for months on end, it looks like stock markets are finally ready to reward businesses for outstanding execution again. Responding to some highly positive earnings calls, shares of at least a few high-growth stocks have started climbing and they could go higher. 

Shares of PubMatic (PUBM 0.33%), SoFi Technologies (SOFI -0.28%), and Duolingo (DUOL -2.39%) are way up since reporting results from the second quarter of 2022. Here's why I'd confidently buy these stocks again despite prices that are significantly higher now than they were at the beginning of August.

1. PubMatic

Shares of this up-and-coming programmatic advertising specialist are up around 41% since the end of July. The stock spiked in response to second-quarter results that showed investors that this sell-side digital advertising business is outperforming its largest competitor.

The second quarter of 2022 was supposed to be an especially tough one for comparisons because people aren't spending as much time watching ads on their devices and televisions as they were a year earlier. This is why it was especially encouraging when the company reported organic revenue growth of 27% year over year.

A proven ability to gain a large share of its rapidly consolidating market without acquisitions is why I'd gladly buy more shares of PubMatic now despite its elevated price. Pubmatic's largest competitor in the sell-side advertising space at the moment is Magnite and it relies heavily on acquisitions of smaller competitors for growth. Both companies reported year-over-year revenue growth of 20% or better in the second quarter of 2022 but Magnite lost $25 million while PubMatic earned $12.6 million.

2. Duolingo

Shares of this education software business are up around 18% in August thanks to a highly encouraging second-quarter earnings call. Duolingo is an education software developer that operates one unified application of the same name. The stock shot up because, despite a challenging environment, the app is converting free users to paid subscribers at a mind-blowing pace. At the end of the second quarter, there were 3.3 million paid subscribers on the books, a 71% gain year over year.

Some of Duolingo's users are native English speakers who want to brush up on a foreign language ahead of a planned trip but this fickle demographic isn't why I keep buying this stock. It's the company's increasingly accepted test of English language proficiency that makes it a screaming buy now. Second-quarter revenue from the Duolingo English test soared 66% year over year to $8 million and it has a long way to go.

IDP Education, an Australian company, is co-owner of IELTS, the most popular English proficiency test at the moment. IDP's testing segment is on pace to record around $350 million in revenue this year. With just $32 million in annualized testing revenue at the moment, there's clearly a lot of room for Duolingo to grow in this space.

3. SoFi Technologies

This is another stock rising quickly on the back of a diversified operation. SoFi Technologies got started around 10 years ago by refinancing student loans and has expanded rapidly. Today, its consumer banking segment can boast of 4.3 million clients engaging with 6.6 million products that include checking accounts, retirement accounts, and credit cards.

In addition to consumer banking operations that could soon be the envy of industry giants like JPMorgan Chase, SoFi also has a business-to-business segment. In 2020, SoFi acquired Galileo, which manages the most popular API used by third parties to build payment services, checking accounts, and debit card programs.

Owning its own technology platform means Sofi doesn't need to pay a third party to roll out new products, plus it's a huge growth driver for the company as a whole. In the second quarter, technology platform revenue soared 85% year over year to $84 million.

With a rapidly growing consumer bank and a technology platform that is second to none, the gains SoFi investors have seen so far this year could be the beginning of a much longer bull run.