Growth is a bedrock characteristic for many great investments. Without an expanding sales footprint, it can be hard to boost profit margins, cash flow, and earnings. Quickly rising revenue is also a clue that a business has found a defensible industry niche and is winning market share.

With that idea in mind, let's look at a few of the quickest-growing large-cap stocks on the market today: Chewy (CHWY -4.85%), Okta (OKTA -2.52%), and Zillow Group (Z -1.86%) (ZG -1.58%).

A person feeding a shaggy dog.

Image source: Getty Images.

1. Chewy

Pet food is an attractive retailing niche, as General Mills, the owner of the Blue Buffalo food franchise, can attest. Amazon knows all about how quickly the e-commerce industry can grow. But Chewy, which sells pet food online, is ideally positioned to capitalize on both of these tailwinds.

Sales in 2020 crossed $7 billion, or roughly double the annual level from just two years earlier. In fact, revenue has been climbing at a 50% annual rate over the last three years. For context, the broader pet food industry is growing at about a 6% compound annual growth rate (CAGR).

Chewy isn't even close to running out of growth avenues. It's pushing into bowls, toys, and other accessories, which can boost profit margins even as they widen its portfolio.

Pet health is another big niche that management is targeting in 2021 and beyond. These wins have executives targeting $9 billion in sales in 2021, compared to $2.1 billion five years earlier.

2. Okta

Okta is the leading seller of identity-management solutions at a time when that enterprise service is seeing explosive demand growth. The consequences of that valuable positioning have been great for shareholders. Sales jumped to $586 million in 2020, compared to $161 million in 2017. That translates to a roughly 50% compound annual growth rate (CAGR).

Okta recently turned to acquisitions as a major growth strategy with its $6.5 billion purchase of Auth0. But the bigger factor that's exciting to bulls is its expanding addressable market, as cloud-service needs soar in the coming decades. That industry outlook, combined with Okta's leading position and growing pool of loyal users, has management feeling confident in predicting over 30% annual growth for the next several years.

3. Zillow

Zillow's attractiveness as a stock isn't unlike Chewy's in that it combines a growing industry niche with a tech-based, customer-centric operating model. The real estate specialist is already much more than just a middleman between homebuyers and sellers. It moves its own inventory and provides mortgage, title, and escrow service, just to name a few services it has broken into over the last few years.

Sales have been rising at an over 40% clip in the last three full fiscal years, thanks, in part, to COVID-19-related demand surges in 2020. But Zillow is still growing sales at 20% through the first six months of 2021 .

Concerns about an industry slowdown are real, and there's no doubt that a sharp residential real estate slump would hurt the business. However, Zillow combines many of the qualities that investors look for in a growth stock, including a dominant position in a growing niche, opportunity for expanding margins, and surging cash flow. That's why simply holding this stock could pay off in spades for investors over the long term.