Chipmaker Nvidia (NASDAQ: NVDA) is often seen the quintessential artificial intelligence (AI) company because it dominates the market for machine learning processors. Shareholders have benefited from that perception. The stock has gained 250% in the past year and Nvidia is now worth $1.2 trillion.

However, Ark Invest believes AI software revenue could hit $14 trillion by 2030, meaning it would eclipse Nvidia's current valuation 11 times over. CEO Cathie Wood elaborated during a recent CNBC interview, "For every $1 in hardware that companies spend on artificial intelligence, they will probably pull $20 through in software."

Accordingly, Ark has stacked its portfolio with AI software stocks, including The Trade Desk (TTD 1.67%) and UiPath (PATH 0.26%). Read on to learn why these stocks are worth buying.

1. The Trade Desk

The Trade Desk operates the largest independent demand-side platform, a type of ad tech software that helps media buyers plan, measure, and optimize ad campaigns across digital channels. To be clear, Alphabet's Google holds far more market share, but consultancy Quadrant Knowledge Solutions says The Trade Desk has superior technology.

One reason for that praise is its Koa artificial intelligence engine, which taps data from 10 million queries every second to improve ad campaign performance. Google undoubtedly has more data, but The Trade Desk believes it has better data, which translates into better AI. That confidence comes from its status as an independent ad tech vendor, meaning it does not own any media content or sell any ad inventory.

By comparison, Google sells ad inventory from properties like Google Search and YouTube while simultaneously helping third-party publishers sell their own inventory. That clear conflict of interest makes brands hesitant to share data with Google, but they have no such reservations regarding The Trade Desk. Case in point: The Trade Desk sources data from 80% of the largest U.S. retailers, providing media buyers with measurement capabilities they cannot find anywhere else. That does indeed hint at better data (and better AI).

The Trade Desk continued to gain market share in the third quarter. Revenue climbed 25% to $493 million, easily topping the 9% ad revenue growth reported by Alphabet, and GAAP net income more than doubled to reach $39 million. But management provided disappointing guidance that caused the stock to plummet.

On the bright side, the recent sell-off creates an opportunity for investors. Morgan Stanley views The Trade Desk as one of 11 companies best positioned to benefit from AI, and The Trade Desk should continue to grow more quickly than the broader ad tech industry, which is projected to expand at 14% annually through 2030. In that context, its current valuation of 17.9 times sales looks reasonable, especially when the three-year average is 28.9 times sales.

Investors should feel comfortable buying a small position in this growth stock today, provided they plan to hold it for at least three to five years.

2. UiPath

UiPath specializes in business automation. Its software blends robotic process automation (RPA) with AI capabilities, allowing customers to (1) analyze tasks and processes to identify automation opportunities, (2) build software robots that address those opportunities, and (3) manage and optimize those software robots.

Morgan Stanley says UiPath is the "clear category leader in robotic process automation, with leading market share in one of the fastest growing software markets." The company has also been recognized as a leader in the adjacent software verticals of process mining, task mining, and intelligent document processing.

UiPath's growth has faltered under economic pressure, but it still reported reasonable results in the second quarter. Revenue increased 19% to $287 million and non-GAAP net income improved to $49 million, up from a loss of $11 million. Investors should look for growth to accelerate as economic conditions improve and UiPath leans into its AI-centric roadmap.

One product of note is Autopilot, a generative AI assistant that will make the UiPath platform more conversational by allowing users to run existing automations, create new automations, and identify automation opportunities with natural language. Another product of note is Clipboard AI, which intelligently copies and pastes information across documents, spreadsheets, and applications.

UiPath also broadened its integration capabilities earlier this year, extending support to custom AI models from vendors like Amazon and OpenAI. For instance, clients can now incorporate ChatGPT into the platform to automate text generation across marketing material, customer service responses, and human resources communications.

On that note, Morgan Stanley believes UiPath could grow revenue as fast as 21% annually over the next decade if its AI ambitions bear fruit. Shareholders should watch top-line growth closely to ensure the company is executing, but that forecast makes its current valuation of 8.4 times sales seem quite reasonable.

Patient investors who can handle volatility should consider buying a small position in this growth stock today.