When investing on a budget, buying fractional shares of top companies is one option. Another is to find stocks with relatively affordable price tags per share. Although it's sometimes the case that the most attractive companies quickly draw attention, which bids up their share prices, it's still possible to find promising stocks for well under $100.

Two great options right now are Novo Nordisk (NVO 2.94%) and Exelixis (EXEL 1.13%). Here's why these healthcare companies are worth investing in today.

1. Novo Nordisk

Novo Nordisk had been flying high since the beginning of the decade, until it ran into significant clinical and regulatory headwinds last year. Its challenges eventually came to a boiling point and the company parted ways with its longtime CEO, Lars Fruergaard Jørgensen, a decision it announced in mid-May.

Physician talking to patient.

Image source: Getty Images.

It's worth noting that Jørgensen led Novo Nordisk through a period of rapid clinical advancements, particularly within its GLP-1 segment. Novo Nordisk's top medicines, Wegovy for weight management and Ozempic for diabetes, continue to deliver excellent results. Jørgensen leaves a solid foundation for the next head of the company to build upon. Given Novo Nordisk's lineup, pipeline, and track record, the stock is likely to recover eventually. Here's one reason why.

Despite recent challenges, Novo Nordisk's revenue continues to grow faster than that of almost every similarly sized pharmaceutical company. In the first quarter, net sales totaled 78.1 billion Danish kroner ($11.9 billion), a 19% increase compared to the same period last year. And on the bottom line, earnings per share were 6.53 DKK ($1), up 15% year over year.

Meanwhile, Novo Nordisk should continue making moves to remain competitive in the fast-growing anti-obesity market, despite incurring some losses recently to its biggest rival, Eli Lilly. Novo Nordisk recently submitted an application to U.S. regulators requesting approval for an oral version of semaglutide, the active ingredient in Wegovy and Ozempic. Current GLP-1 therapies are typically administered by injection.

Novo Nordisk also has several early-stage assets in this field, including a potential triple agonist -- a GLP-1 medicine that also mimics the action of two other gut hormones.

Elsewhere, the FDA (U.S. Food and Drug Administration) accepted the company's regulatory application for Wegovy in treating metabolic dysfunction-associated steatohepatitis (MASH) and granted it priority review; it's also under review by regulatory authorities for this indication in Europe. There is only one FDA-approved medicine for MASH, despite the millions of patients affected and the condition's growing prevalence.

Lastly, Novo Nordisk is making progress across its pipeline, including in other therapeutic areas, such as Alzheimer's disease, where it has upcoming data readouts. Recent headwinds notwithstanding, the company remains well- positioned to lead in diabetes and obesity care for the long term, while also making strides in other areas. The stock could still deliver superior returns to patient investors. And with shares trading for just under $71 each, $100 can get you one of them.

2. Exelixis

Exelixis is an oncology specialist; its most important medicine, Cabometyx, treats some forms of liver and kidney cancer. Some investors have long been worried about Exelixis' overreliance on this drug, and with good reason. In the first quarter, Exelixis' revenue came in at $555.4 million, up 30% year over year; Cabometyx's sales came in at $510.9 million.

If something were to happen to this medicine -- like generic competition -- it would be a disaster for the company. Fortunately, Exelixis fended off this threat last year with a significant win in a legal battle against a generic-drug manufacturer, which should keep its cheaper competitor off the market until 2030.

Still, Exelixis has continued to grind out indications for its crown jewel. One of the latest was in treating metastatic, well-differentiated pancreatic neuroendocrine tumors, a nod it received in March. Cabometyx has long been one of the top-prescribed cancer medicines of its kind in renal cell carcinoma (kidney cancer), and additional indications have helped it continue to grow its sales.

Exelixis should maintain that momentum through the end of the decade. Meanwhile, it's developing other cancer medicines. It tends to target areas of the field with high unmet need, such as metastatic colorectal cancer.

Despite being the second leading cause of cancer death worldwide, colorectal cancer is highly treatable when caught early -- but once it has metastasized, five-year survival rates drop. Exelixis is developing zanzalintinib to address this problem. The medicine is being tested in other clinical trials as well.

Exelixis' revenue and earnings should maintain a solid upward trajectory as it secures more clinical and regulatory wins. That's how the stock can deliver strong returns. Shares are trading for about $43, so you can grab two of them with $100.