3 Top Stocks to Buy in December

Black Friday is over. Cyber Monday has come and gone. But that doesn't mean the shopping season is over – especially if you're an investor wanting to put some of your money to work for you. Here are three top stocks to buy in December.

1. MercadoLibre

MercadoLibre (NASDAQ: MELI) is the top dog in the Latin American e-commerce market and one of the biggest players in the region's fintech market. Its stock has delivered a compound annual growth rate of more than 30% over the last five years and 10 years.

But this top dog has been whimpering a bit in recent months. MercadoLibre's shares are down roughly 20% below the all-time high reached in late June. Much of this decline stems from Amazon's (NASDAQ: AMZN) increased competition against MercadoLibre on its home turf in Latin America.

Should investors be worried about the threat that Amazon poses? I don't think so. Instead, I view the sell-off as an excellent opportunity to buy one of the best international stocks around.

E-commerce adoption in Latin America remains nearly a decade behind that of the U.S., with market penetration as a percentage of total retail sales in the mid-teens. Like Amazon, MercadoLibre has become a leader in digital advertising, another major avenue for growth. On the fintech side of MercadoLibre's business, the company still has significant expansion opportunities, particularly in Argentina, Chile, and Mexico.

Image source: Getty Images.

2. TransMedics Group

TransMedics Group (NASDAQ: TMDX) is disrupting the organ transplantation market with its Organ Care System (OCS). The standard of care in transporting donor organs has been cold storage for decades. However, this approach often results in organs being damaged during transit and rendered unusable. Post-transplant complications can also frequently occur.

OCS addresses these issues by keeping donor hearts, lungs, and kidneys alive during transportation. It uses a process called warm perfusion to pump oxygen-enriched blood and nutrients through the organs. Healthcare professionals can also actively monitor the donor organs throughout the entire process. TransMedics Group is the only company with warm perfusion technology approved by the U.S. Food and Drug Administration that can handle multiple organs.

One significant advantage of using OCS over cold storage for transporting donor organs is a substantial increase in utilization. Thanks to TransMedics' technology, over 80% of donor hearts and lungs that would typically not be usable with cold storage can be transplanted to recipients. Roughly twice as many donor livers can be transplanted with OCS compared to cold storage.

The transplanted organs have fewer problems when they're transported by OCS, too. The reductions in severe post-transplant complications are impressive: 43% for livers, 50% for lungs, and 65% for hearts.

TransMedics' market cap is still only around $5 billion. That's a bargain valuation, in my view, considering the company's growth prospects. TransMedics is expanding into Italy in 2026, marking a significant first step toward entering other European markets. It's also developing a version of OCS for kidneys. That could be a game changer, considering that the number of kidney transplants in the U.S. exceeds the combined number of heart, liver, and lung transplants.

3. Vertex Pharmaceuticals

Vertex Pharmaceuticals (NASDAQ: VRTX) dominates the cystic fibrosis (CF) market for a simple reason: It has the only approved therapies that treat the underlying cause of the genetic disease. Vertex's nearest potential rivals are only in phase 2 clinical testing. I think the big drugmaker's head start might be insurmountable, especially with its newest CF therapy (Alyftrek) offering greater efficacy and convenience than its current best-seller, Trikafta/Kaftrio.

But while Vertex has made a fortune in CF, the company could have even greater prospects in other indications. Non-opioid pain drug Journavx looks like a sure-fire blockbuster. It's already approved for treating acute pain and is being evaluated in late-stage studies targeting painful diabetic peripheral neuropathy.

Vertex has already begun a rolling Biologics License Application (BLA) submission for povetacicept in treating IgA nephropathy. This chronic kidney disease affects around 300,000 patients in the U.S. and Europe, as well as more than 750,000 in China. By comparison, CF affects an estimated 109,000 patients worldwide.

The biotech innovator also expects to file for regulatory approvals of zimislecel in treating severe Type 1 diabetes next year. Vertex's goal is for this program to serve as a steppingstone in developing a functional cure for the disease that affects approximately 3.8 million people.

Keith Speights has positions in Amazon, MercadoLibre, and Vertex Pharmaceuticals. The Motley Fool has positions in and recommends Amazon, MercadoLibre, TransMedics Group, and Vertex Pharmaceuticals. The Motley Fool has a disclosure policy.