The stock market continues to keep investors on their toes, with the S&P 500 down roughly 19% year to date but up 6% over the past six months. As we approach the start of a new year, you're likely evaluating the state of your portfolio and considering what stocks you want to buy, hold, or add to. 

While growth stocks have fallen out of favor with many investors over the past year, and there are undoubtedly growth-oriented companies that will not return to their former highs, some winners remain. Amazon (AMZN -0.29%), Shopify (SHOP -0.64%), and Veeva Systems (VEEV 1.04%) are three winners to consider adding to your portfolio before the year is out. If you're worried about another sell-off in 2023, each of these companies has what it takes to endure for the long run.

1. Amazon

Amazon needs no introduction. The tech behemoth has remained a winner for investors throughout its fair share of market cycles, surviving the burst of the dot-com bubble and the Great Recession. It hasn't been all sunshine and rainbows for investors in the 25 years since Amazon became a publicly traded company. For example, at the height of the dot-com bubble crash two decades ago, Amazon shares shaved as much as 90% off their total value.  

However, long-term investors in Amazon have been rewarded with compounded returns again and again. Over the trailing decade, Amazon has delivered a generous total return of more than 609% for investors.

Amazon's success, while so many other tech businesses have floundered and failed over the years, can be attributed to a variety of catalysts. These range from the strength of its leadership to the diversity of its business model to its track record of disrupting lucrative, fast-growing markets. As things stand today, Amazon remains a focal presence in the worlds of e-commerce and cloud computing while continually expanding its footprint in key markets ripe for additional disruption like telehealth, grocery delivery, and entertainment.

Amazon controls roughly 38% of the e-commerce market in the U.S. Bear in mind that the U.S. e-commerce market accounts for a significant slice -- nearly $905 billion -- of the global addressable e-commerce space, which is worth $5.7 trillion.

Amazon's other key business segment, Amazon Web Services, saw revenue rise 27% year over year in the most recent quarter alone, even as overall revenue growth remained steady but moderated at 15%. The company still beats out Alphabet and Microsoft as the top dog in the cloud computing space, with a 34% share of this $57 billion market.

Near-term economic factors like rampant inflation that increase the cost of doing business and declines in consumer spending will inevitably impact the pace of growth for Amazon. However, these factors aren't specific to Amazon and are impacting companies across virtually every sector of the market. Over the long term, Amazon's robust collection of businesses and strong balance sheet (the company had $58.6 billion in cash and investments on hand at the end of the most recent quarter) can help it weather the storm and continue delivering growth for investors in the years ahead.  

2. Shopify

Shopify's journey over the past year has been anything but paved smoothly, and long-term investors in the stock have certainly been on a bumpy ride. Shares of Shopify have cratered by 72% over the last year as investors have increasingly lost faith in growth-oriented businesses and searched for more stable vehicles in which to invest their capital.

As a shareholder of Shopify, I've had to revisit my thesis for owning the stock several times over the past year. However, I've continued to hold on through the storm for a variety of reasons. First, much of the sell-off of Shopify's shares that investors have witnessed hasn't been tied to long-term, durable changes in the underlying business. Meanwhile, Shopify remains one of the leading e-commerce platforms in the world, used by everyone from mom-and-pop businesses to large global brands.

Even as growth has slowed compared to pre-pandemic levels -- and it would have been unrealistic to think that elevated boom would continue indefinitely -- Shopify has continued to streamline its services and tools for merchants, invest in its fulfillment network, grow revenue, and increase its cash position. While elements like the macro environment, changes in consumer spending, and Shopify's aggressive growth strategies have pushed down on its bottom line, those net losses are narrowing (the company shaved its net loss from $1.2 billion in the second quarter to $158 million in the third quarter).

Shopify leads the e-commerce platform market in the U.S. with a 25% market share. It also holds the No. 2 spot globally, with a market share of 19%, which is second only to WooCommerce. Taking a step back and looking at Shopify's growth over the prior decade, the company has delivered total revenue growth of 585%, while its operating cash flow has increased by 6,280%.

Personally, my thesis for buying Shopify remains intact, and not because short-term headwinds such as a potential recession won't likely impact its business. But over the long term, I still believe the company can keep executing on its vision as a leading one-stop shop for merchants to launch a business of any kind from anywhere in the digital age. 

Shopify's continued growth and massive market footprint bode well for its future success, well beyond what may be in store for investors in the next one to two years. For risk-tolerant investors, the stock remains a compelling buying opportunity, even in the current down environment. 

3. Veeva Systems

Like most other cloud computing stocks, it's fair to say that it hasn't been a banner year for Veeva Systems' stock. Shares are trading down about 34% year to date, but again, these aren't tied to company-specific factors or durable headwinds. 

Veeva Systems is a bit unique in the cloud stock universe in that it focuses its services exclusively on the life sciences industry. It does so at a massive scale, with well-known clients like Merck and Moderna relying on its software to streamline daily operations.

Over the trailing-10-year period, Veeva Systems has grown its annual revenue and earnings by respective amounts of 1,300% and 2,200%. It has also increased its operating cash flow by 2,400% in that time frame. The stock has been a high performer for investors over the years, too, delivering a total return of nearly 400% in the trailing 10-year period. Meanwhile, analysts think the company can grow its annual revenue by 13% on average for the next five years alone.  

It's true that many companies are slashing costs right now, and some cloud businesses are taking a hit because of it. Veeva recently announced that it was cutting ties with Salesforce, a long-term partner in serving clients in the pharmaceutical and biotech industry, once its contract expires in 2025. However, Veeva continues to expand and build upon its existing partnerships, with more than 1,000 customers and counting.

The types of customers that Veeva Systems serves also tend to be more resilient than most in a recessionary environment due to the non-cyclical nature of their industry. And even cost-cutting measures are unlikely to impact Veeva Systems to a great extent over the long term. The company's software and services are an essential component of operations for some of the world's largest biotech and pharmaceutical companies to function on a daily basis.

Its software helps these companies accomplish numerous tasks, including streamlining the clinical trial process, managing regulatory registrations and submissions, simplifying data management, and managing quality control and compliance initiatives. This gives Veeva Systems tremendous room to grow both in and beyond the current environment. As such, for long-term investors, the stock could pose a welcome addition to a well-diversified portfolio.