Tech stocks might not be the high-flying stars they used to be, but there's one corner of the industry that's burning white-hot with investors right now -- artificial intelligence (AI).

Since the sudden and sharp rise of ChatGPT, the market has been eager to get its collective money-making hands on good AI stocks. Yet it's early days for AI as a stand-alone business, and investors have to be careful. With that in mind, here's a look at three of the most promising publicly traded AI companies -- C3.ai (AI 2.26%), UiPath (PATH 0.28%), and Schrödinger (SDGR 2.74%). 

1. C3.ai

C3.ai concentrates on providing AI applications and software solutions to enterprise (corporate) clients. These can be utilized for a range of different functions, including trend forecasting and risk assessment. 

While the company operates in a segment investors can't get enough of these days, numerous questions have been raised about the way it does business. It indisputably has a divestment issue, with over 70% of its revenue coming from a single sector (oil and gas). Compounding that, more than 30% of sales derive from one client, leading oilfield services company Baker Hughes.

And this relationship might be under strain. In April, short seller Kerrisdale Capital wrote a scathing report about the state of C3.ai's business. In it, the firm alleged that C3.ai's relationship with Baker Hughes is "fundamentally broken," with the client notably reducing its commitments to the AI company. Additionally, it accused C3.ai of using recent pricing adjustments and accounting jiu-jitsu to obscure operational weakness.

The company quickly rebutted many of Kerrisdale's accusations. But in many investors' eyes, the damage has been done -- the stock hasn't recovered from the short-seller assault.

Meanwhile, despite its effective attachment to the AI trend, C3.ai is running a highly unprofitable business. C3.ai has posted a net loss in nearly every quarter since going public in 2020, and on an annual basis, that shortfall deepened to more than $192 million in fiscal 2022 from 2021's deficit of nearly $56 million. This is a stock I'd be wary of just now.

2. UiPath

UiPath specializes in a discipline called robotics process automation (RPA). This basically means it programs and designs machines to perform tasks humans might struggle to do, or find generally unappealing.

Its rather unimaginatively named UiPath Business Automation Platform promises to help enterprises address their "automation needs across each step of the journey."

This approach seems to be resonating with customers. The company's revenue has been snowballing, leaping from $148 million in its fiscal 2019 to more than double that the following year, then a steep rise to just over $1 billion for fiscal 2023.

Staying on the cutting edge of RPA and building robots requires plenty of financial commitment, so like C3.ai, UiPath typically posts a loss on the bottom line. In contrast to its peer, however, those shortfalls have been narrowing -- the fourth-quarter net loss was under $28 million, a much better figure than the over $63 million in the same quarter of 2022.

The company had a very successful IPO in 2021, with its issue bringing in over $1.3 billion. It's been fairly cautious with cash -- as of the end of January it had a $1.4 billion pile of greenbacks in its coffers. At the same time, its indebtedness was comparatively low and manageable, with $56 million in long-term borrowings.

So it's got a long runway, and meanwhile it offers advanced solutions in a process (automation) that should only get more popular with businesses aiming to save money. UiPath stock isn't a bargain on its valuations, but the company certainly has significant potential and more than sufficient financial resources. As such, it's well worth considering as an investment.

3. Schrödinger

One intriguing niche AI stock is Schrödinger, named after the celebrated physicist best known for his Schrödinger's Cat thought experiment. Like the man, Schrödinger the company aims to push the world forward through experimentation -- it leverages AI technology for its software platform, which helps pharmaceutical and biotech companies with drug discovery. 

This is a critical process, as an effective medication targeting a stubborn or debilitating medical disorder can bring in billions of dollars of revenue for its developer. Schrödinger's platform basically introduces a monster computer brain into the process, giving clients a big leg up on discovery.

It's a compelling proposition, and Schrödinger's revenue has been consistently rising thanks to it. But biotech/pharmaceuticals might be only the first of many customer bases for the company, since its technology can be adapted to aid processes in other fields too. Admirably well aware of this, Schrödinger currently has its eye on sectors such as aerospace, semiconductors, and energy.

True to its nature as an AI company, young Schrödinger doesn't yet offer the comfort of habitual bottom-line profitability. Its losses aren't catastrophic, however, and they've been worse -- the $27 million in red ink in the most recently reported quarter was the lowest in at least the past five quarters. At the same time, revenue continues to head north, with a 23% year-over-year improvement in said quarter (to almost $57 million).

Any company with a compelling product that has excellent potential to scale up dramatically is a serious candidate for a good stock portfolio. Schrödinger definitely fits this bill.