While no stock is immune from market swings, investors don't have to worry about short-term dips. Stocks ultimately follow the growth (or lack thereof) of the underlying business. What makes a company unstoppable is its ability to deliver sustainable growth in revenue and profits over the long term. That's what creates lasting wealth for shareholders.

Apple (AAPL 1.67%), MercadoLibre (MELI -0.98%), and Airbnb (ABNB 0.30%) are all showing signs of real staying power, which could lead to many years of magnificent returns. Let's see why these Motley Fool contributors believe these companies are unstoppable.

Invest in the products people can't live without

John Ballard (Apple): When trying to identify a company that could be unstoppable, you want to think of powerful brands that millions of people rely on every day. On that criteria alone, it's hard to not to like Apple, whose flagship product, the iPhone, is an indispensable device for many.

While sales could soften during a severe economic downturn, investors shouldn't be concerned about that, because Apple has a very loyal customer base. This is noted by its consistently high customer satisfaction scores and its growing installed base of active devices, now over 2 billion. Plus, the company introduced several new services in recent years that are driving consistent year-round revenue, like Apple TV+, Apple Card, Apple Pay, and more.

Apple will continue to drive repeat upgrades as it invests in artificial intelligence to make its products even better. This will create a stickier attachment between customers and their devices.

Investors can't go wrong investing in strong brands that generate massive cash flows. Over the last four quarters, Apple generated a whopping $97 billion in free cash flow on $387 billion of revenue. It's got more cash than it knows what to do with, which is why management continues to plow funds into share repurchases and quarterly dividend payments.

It's for these reasons Apple is an unstoppable stock to consider buying this month.

An e-commerce superstar

Jeremy Bowman (MercadoLibre): If you're looking for unstoppable stocks to buy this month, look no further than MercadoLibre, the Latin American e-commerce company that has been a top performer on the stock market over its history.

MercadoLibre just offered a reminder of why the stock is still a top buy in its first-quarter earnings report. Currency-neutral revenue in the quarter jumped 58% to $3 billion with total payment volume nearly doubling, up 96% to $37 billion. Gross merchandise volume, meanwhile, also surged 43% to $9.4 billion. MercadoLibre's strength across e-commerce and digital payments makes it unique, and the company has also built formidable businesses in logistics with Mercado Envios and lending with Mercado Credito.

Unlike its U.S-based e-commerce counterparts, MercadoLibre has continued to put up strong growth over the last year even as the pandemic tailwinds slowed, a sign the company continues to gain market share and is penetrating a large market that is still behind the U.S. in e-commerce adoption. MercadoLibre's profitability also ramped up as it gained scale in e-commerce and payments. Operating margin in the first quarter jumped from 6.2% in the quarter a year ago to 11.2%, giving it an operating income of $340 million.

As the company builds scale with its first-party e-commerce business and digital payments investments, it's been able to layer on higher-margin businesses like its third-party marketplace, its credits business, and advertising, following in the footsteps of Amazon.

The company doesn't provide guidance, but its growth momentum looks as strong as ever, and the company should continue to gain market share as it penetrates the massive Latin American market.

It's about time for travel to be disrupted

Jennifer Saibil (Airbnb): It's not surprising that the travel industry has been upended. For decades it was dominated by large hotel chains, whether of the luxury or budget variety, with a sprinkling of vacation rentals abounding once the internet made them more accessible. Airbnb took that concept to new heights, and its platform, which matches renters and hosts, ballooned into the premier travel site of its kind.

Growth is robust but is easing a bit. Triple-digit sales growth that marked a rebound from the pandemic has decelerated to double digits. Revenue rose 24% year over year in the 2022 fourth quarter to $1.9 billion. But the growth runway is very long. Airbnb offers an agile system that can adapt to changing consumer needs and trends, as opposed to legacy hotel companies that take tons of time and money to get new buildings up.

Travelers are using the platform to vacation in a different way, such as living in new areas. That's both as a vacation, where renters are exploring out-of-the-way areas that the big chains aren't accessing, and full-time living. Rentals of 28 days or more continue to be an important segment, remaining at 21% of bookings in the fourth quarter.

Airbnb has also become sustainably profitable. It posted net income for the past three consecutive quarters as well as an annual profit in 2022. It's also awash in cash, ending the year with $3.4 billion in free cash flow.

Airbnb made a bold move when it went public at the end of 2020 amid heavy sales declines. But investors scooped it up regardless, partially due to its incredible market opportunity, and partially due to the general initial public offering craze and robust bull market that was taking place at that time. The price skyrocketed, and it's now down 44% since its highs in 2021.

At this price, shares trade at a price-to-earnings ratio of 43. That's not incredibly cheap, but it's down to a more reasonable level. With Airbnb's opportunities, investors could consider that valuation low enough to purchase shares.