Building a $1 million retirement nest egg is the dream of many investors. With the appropriate strategy, allocation, and investing time horizon, this isn't an impossible goal by any means. As you diversify your basket of stocks to work toward this achievement, it's important to select quality businesses across a wide variety of sectors with multiple catalysts to sustain continued returns over a period of years.

For example, if you were to invest $200,000 in the stock market right now, promising companies with innovative, industry-leading businesses ripe for future growth could foreseeably compound that investment by 5 times or more in the next decade. With that said, here are two such stocks that could help you build out your retirement plan. 

1. Upstart 

Upstart (UPST 6.48%) is dealing with extremely choppy market waters right now; however, looking beyond these events to the company's long-term prospects, an altogether brighter picture forms. To understand why, one has to take a deeper look into the inner workings of Upstart and its business, which is driven by artificial intelligence and machine learning. The company operates a lending marketplace that revolves around its innovative technology platform, which leverages more than 1,600 data points to assess the creditworthiness of any given consumer. In other words, it doesn't just the FICO score but atypical factors like education and income to help determine this.

By using a far broader range of factors to determine whether an applicant ought to be approved for a loan, as well as the platform's predictive capabilities that calibrate to the economic environment to assess the likelihood of that applicant to default, Upstart has not only been able to democratize the long-stale lending arena but also lower risk for institutional partners with more inclusive and real-time data.

Moreover, because Upstart's platform is constantly learning, this not only enables it to adjust to the most current economic conditions, but this also means that more of the company's loan applications are being handled on a fully automated basis.

In Upstart's full-year 2022 earnings report, management said that 82% of all loan applications on the platform were fully automated -- the highest level of automation its model has reached in the history of the company. Moreover, 88% of all small-dollar loans are now automated. On top of that, as of the end of 2022, Upstart's model had learned more in the prior seven months than it had in the entire 30 months before that.

During 2022, Upstart's number of bank and credit union partners soared 120% from 2021, and its network of auto dealers jumped more than 90% year over year. Bear in mind, the auto lending market alone represents a near $800 billion opportunity, and as of the end of 2022, the company had the second-fastest-growing auto retail software in the country.  

As Upstart's platform is constantly learning, a challenging economic environment is inevitably going to mean that it approves fewer loans than it would in a situation where the risk of default is lower, but this would also indicate the exact opposite would happen in a more buoyant economic landscape. At the same time, the combination of institutional partners funding far fewer loans right now and a drop in consumers applying for loans has contributed to the declines in Upstart's top and bottom lines recently. While investors will need to continue watching these factors closely in the quarters ahead, it's important to differentiate broader economic headwinds from headwinds tied directly to Upstart's business. 

The fact that the company is expanding market share, boosting platform automation, and rapidly growing its partner network even in a decidedly bleak lending environment is notable, and could prime the business for a relatively rapid upward trajectory once the economic environment improves and interest rates come down. Even a conservative position in this top growth stock could yield tremendous results over the next five to 10 years when paired with a wide selection of investments in a buy-and-hold investment portfolio. That potential may be too intriguing for some investors to overlook while the stock's currently trading down.

2. Teladoc 

Teladoc (TDOC 3.50%) investors -- and I am one of them -- have faced more than their fair share of volatile market days over the past year. While shares of this healthcare stock are still down 64% from 12 months ago, they've risen roughly 15% since the start of 2023. The market has been far less kind toward unprofitable, growth-oriented businesses in the current economic environment, and Teladoc currently fits squarely into both categories.

The full 2022 year saw Teladoc achieve some notable goals, while falling short on other fronts. Revenue totaled $2.4 billion for the 12-month period, an 18% increase from 2021. Adjusted earnings before interest, taxes, depreciation, and amortization (EBITDA) was down year over year, but still hit $247 million. Teladoc also continues to see rapid adoption across a wide range of its healthcare services, with its teletherapy arm BetterHelp alone posting revenue growth of 29% year over year in the final quarter of 2022.

Teladoc reported a third impairment charge in Q4 of 2022 after having significantly shaved its net losses in the prior quarter. Specifically, it ended the 12-month period with a net loss of $13.7 billion, almost entirely due to impairment charges related to writing down the value of its 2020 Livongo acquisition. Here's the thing, though: While this loss is unpleasant to look at as an investor, these were non-cash impairment charges. In other words, paper-only net losses, which are not the same as actual operational losses.

Even though Teladoc overpaid for that acquisition, its contribution to its overall mission of disrupting the still underserved chronic care solutions market remains a notable green flag for the long-term future of the integration of these two businesses. CEO Jason Gorevic noted the following about its chronic care segment and broader platform expansion on the company's 2022 earnings call:

Access to our platform is available to over 80 million individuals in the U.S. today, primarily through our relationships with employers and health plans. Over 50% of that population has access to more than one of our products. And when I look at our suite of chronic care solutions, 30% of enrollees are now utilizing more than one chronic care product. Our BetterHelp offering provided over 1 million individuals with access to mental healthcare over the past year, many of whom are unlikely to have received any care at all, if not for our services.

Our platform enabled over 22 million visits across specialties last year and over 0.5 billion digital health interactions with an unmatched consumer experience and a net promoter score over 60. That breadth and scale is unrivaled in the industry and gives us a strong foundation on which to expand.

Teladoc remains the premier telehealth platform in the U.S., and the increasing diversity and adoption of its offerings bode well for its ability to continue expanding its market share in the years ahead. Management has been clear that moving back to profitability is a key goal for the future. The investments Teladoc is making now could yield robust returns for the company and its shareholders in the years ahead. As such, given Teladoc's long trajectory for growth, forward-thinking investors may find any dips in the stock to be too good to pass up.