The S&P 500 (^GSPC -0.19%) is up 18% year to date, but strategists at Goldman Sachs, Yardeni Research, and Capital Economics believe the benchmark index is headed higher in the coming quarters. Their upbeat forecasts imply upside ranging from 4% to 21% over the next 18 months, reflecting a positive shift in market sentiment brought on by cooling inflation and stronger-than-expected economic growth.

Here are two unique growth stocks to buy now.

1. Etsy

Etsy (ETSY -3.13%) reported mixed financial results in the first quarter. Gross merchandise sales declined 5% to $3.1 billion as elevated inflation dragged on consumer spending. Yet, revenue jumped 11% to $640 million, an acceleration from 5% growth in the prior year, as Etsy flexed its pricing power by raising transaction fees. But earnings still fell 40% to $0.60 per diluted share as operating costs swelled due to ongoing product development initiatives.

Fortunately, consumer sentiment is trending higher, and Etsy should be able to grow more quickly (and more profitably) as the economy regains its momentum. Etsy occupies a unique niche in e-commerce in that it focuses on non-commoditized goods. Specifically, the company caters to sellers of artisanal, vintage, and handmade products, many of which can be customized or personalized, creating a shopping experience that is altogether different than what retailers like Amazon and Walmart provide.

Etsy may not be right for every occasion, but its niche focus is perfect for certain occasions and its business model is clearly resonating with consumers. Etsy is the sixth most popular online marketplace in the world as measured by monthly visitors. Yet, the company has hardly scratched the surface of what it could become. Management currently values its addressable market at $466 billion, but that figure could reach $2 trillion as more products are sold online.

To make good on that opportunity, Etsy is working its way through an ambitious product roadmap focused on improving the buyer experience. Recent changes include the launch of a purchase protection program that guarantees refunds for damaged or lost orders, and the expansion of a star seller program that spotlights Etsy shops with superior customer service. Those efforts should help the company build trust with buyers over time.

Etsy is also focused on improving search and discovery, and CEO Josh Silverman believes recent breakthroughs in generative artificial intelligence (AI) could be particularly helpful here. By leaning on large language models, the search engine could support visual or natural language queries. That means, rather than browsing blue dress shirts at random, buyers could ask the AI to recommend blue shirts suited to an upscale restaurant in Los Angeles, or they could ask the AI to recommend blue shirts similar to a specific image.

Currently, shares trade at 4.8 times sales, a bargain to the three-year average of 10.3 times sales. That is a reasonable price to pay for this unique growth stock.

2. Atlassian

Atlassian (TEAM -3.75%) builds tools that help business teams work more productively. Its best known product is the Jira platform, a suite of work management and IT service management software that helps technical teams complete coding projects, non-technical teams plan business projects, and IT support teams deliver efficient customer and employee service. But Atlassian also offers solutions for team collaboration and enterprise planning.

Atlassian is unique for several reasons, but it's go-to-market strategy stands out. The company eschews direct sales tactics, relying instead on viral marketing and self-service sales automation to distribute its products. That keeps sales and marketing costs low, which allows Atlassian to outspend its peers on research and development. That advantage hints at greater agility, and it has arguably translated into superior software.

Atlassian is also unique in its ability to connect technical teams, non-technical teams, and IT support teams on a common platform. That not only makes life easier for customers, but it also allows Atlassian to land new clients through almost any department, then expand across the organization. Not surprisingly, industry experts have recognized the company as a leader in several software verticals, including DevOps, IT service management, and enterprise planning.

Atlassian reported reasonably strong financial results in the most recent quarter, though growth did slow as businesses continued to pull back on IT investments in response to difficult economic conditions. Revenue rose 24% to $915 million, a modest deceleration from 30% growth in the prior year, and non-GAAP net income climbed 26% to $0.54 per diluted share. 

Looking ahead, Atlassian is well positioned to accelerate its growth trajectory as economic conditions stabilize. The company has a strong competitive position in a $29 billion market that management says its growing at 14% annually. Yet shares trade at 13.4 times sales, a discount to the three-year average of 26.2 times sales. That is a reasonable price to pay for a unique growth stock like Atlassian.