After a bad end to 2018, there are deals to be had. Even growing businesses weren't spared the downturn; the stock market tanked 14% during the last quarter of the year, as measured by the S&P 500. The good news is that investors with a long-term outlook can pick up some growing companies at steep discounts to where they were just a few months ago.

Three such companies that are expected to keep expanding in the years ahead are Skechers (NYSE:SKX), Teladoc (NYSE:TDOC), and Carvana (NYSE:CVNA).

A shoe company with something to prove

Nicholas Rossolillo (Skechers): 2018 wasn't a great year for Skechers stock. Though sales churned higher, especially internationally, investors were disappointed with profit margin as the company sacrificed the bottom line to promote expansion. The result was a 40% drop in share value on the year.

Here's the business color surrounding that 40% bludgeoning: Sales grew 11.5% through the first three quarters of 2018, but earnings per share were up only 3.2%. Much of that had to do with operating expenses increasing 17.3%, which includes spending to support double-digit growth in China. Still, growth is growth, so why the downbeat mood? It all has to do with a slowdown. For comparison, Skechers' sales and earnings rose at clips of 16.9% and 13.4%, respectively, in 2017.

Thus, it was all about the cool-off that troubled shareholders last year. Not to worry, though: Management forecast a return to sales growth in the mid-teens during the fourth quarter. Due to the size of its addressable market outside the U.S., that growth rate could have some runway ahead; Wall Street seems to agree. The trailing-12-month price-to-earnings ratio sits at 22.3, but forward P/E based on analyst expectations is only 13.3 -- implying big gains for the bottom line in the quarters ahead, as the fruits of all that spending are realized. Given the favorable valuation and Skechers' growth trajectory, this one is worth adding to your buy list.

Check out the latest Skechers earnings call transcript.

The interior of a Skechers store, with shoes and clothing on display

Image source: Skechers.

Filling a need for lower-cost quality healthcare

Chuck Saletta (Teladoc Health): Not all medical needs require extensive in-person visits with your doctor. Some issues can be confirmed with a visual inspection or a question-and-answer session. Others require lab tests that your doctor is going to send you elsewhere for anyway -- so why bother with the office visit?

Enter Teladoc Health, a leading company in the field of telemedicine. To the extent you can get the medical care you need without traipsing into the doctor's office and sitting in a germ-infested waiting room, it's a win for you. To the extent your doctor -- or some doctor in your network -- can spend more time on diagnosis and treatment without the overhead costs of a facility, it's a win for the doctor. To the extent the costs of providing such services are lower than a traditional visit, it can be a win for both.

Telemedicine has the potential to get people quicker access to medical care at lower costs than traditional office visits. While not all health needs can be handled over the phone or a videoconference, those that can include maintenance of lifelong conditions like congestive heart failure or type 1 diabetes.

Teladoc Health is not currently profitable, but it's expected to be able to grow its revenue by around 30% in 2019, and it has more cash than debt on its balance sheet. The balance sheet and solid growth trajectory are decent reasons to believe that Teladoc Health could be worth owning over the long haul. A share price that has fallen significantly off its highs, and has only partially recovered, makes now a better time to consider buying than when investors were looking at Teladoc shares this past fall.

Check out the latest Teladoc earnings call transcript.

A retailer with explosive growth

Daniel Miller (Carvana): Carvana, a used-car retailer changing how people can buy cars through its online platform and unique vending machines, has watched its stock price jump 73% over the past 12 months. But January offers investors an opportunity to jump on board, as the stock has cooled since its September high:

CVNA Chart

Data by YCharts.

It might sound counterintuitive to buy stock in an auto retailer when headlines are warning of the slowing new-car retail environment, but Carvana's scenario is different. As prices for new vehicles continue to rise, many consumers are seeking alternatives, including much cheaper used vehicles. In fact, during the third quarter of 2018, used-car average transaction prices (ATPs) were almost $16,000 cheaper than for new vehicles, potentially fueling demand for used vehicles.

Furthermore, with more off-lease vehicles including more popular segments such as crossovers and SUVs, the used-vehicle market is more compelling than when it was flooded with passenger cars -- and Carvana's growth has already been incredible. During the third quarter, Carvana grew retail units sold by 116% and total revenue by 137%. In fact, Carvana sold more vehicles in the third quarter than it did in 2015 and 2016 combined.

In the near term, Carvana will continue to expand its number of markets with as-soon-as-next-day delivery, and it will focus on increasing its gross profit per unit (GPU). It's well-positioned to continue its explosive growth, as it grows its footprint more profitably, and as used vehicles become a more compelling alternative to new vehicles.

Check out the latest Carvana earnings call transcript.