With all the major indexes still well off their 2021 highs, we know the market will eventually rebound, but it's never easy to predict when. History shows us that markets rise much further, and for longer stretches, than when it falls.

Shares of e-commerce giant Alibaba Group (BABA 1.61%) and high-tech lending platform Upstart Holdings (UPST -1.28%) are currently trading down over 70% from their all-time highs. These market leaders are investing heavily in artificial intelligence to power the future and look poised for a big rebound. Here's why these growth stocks are good choices if you're looking to juice your returns.

1. Alibaba

Alibaba is the leading e-commerce and cloud services provider in China. The stock is down 74% from its previous highs after an intense round of regulatory scrutiny of big tech platforms in China, while also rubbing elbows with U.S. regulators. But these problems are fading behind it now, leaving a dirt cheap stock for the taking.

Alibaba's Tmall and Taobao dominate e-commerce in China. Its commerce businesses make up 69% of the business but saw a 1% decline in revenue in the most recent quarter. Alibaba also operates AliExpress, Lazada, and other businesses, which make it a formidable global e-commerce operation. Altogether, these international platforms made up 8% of total revenue but grew 18% year over year in the December-ending quarter.

China has been wrestling with a weak economy that pressured consumer spending. But these headwinds will eventually turn into growth tailwinds, as Alibaba noted that consumer and business confidence was already starting to rise in February. A recovering Chinese economy is a major catalyst for this cheap stock to take off.

As one of the leading tech company's in the world, Alibaba also has a cash fortress sitting in the bank. It ended the last quarter with $55 billion of cash and strong cash flows. This gives the company ample resources to invest in artificial intelligence (AI). The Chinese government has previously stated a goal to be a world leader in AI, and that should accrue to Alibaba's benefit as a tech leader.  

Alibaba recently announced Tongyi Qianwen, a new AI-driven language model similar to OpenAI's ChatGPT. The company plans to integrate this technology into its shopping apps and other services. 

You don't need to run fancy spreadsheets to see that the stock is likely selling significantly below its future value. At a price-to-earnings ratio of just 9 based on this year's consensus earnings estimate, the company's growth prospects are heavily discounted. Investors who buy and hold the stock for the long term should do very well.

2. Upstart Holdings

Upstart Holdings has a lot of promise to deliver market-thumping returns over the next several years. It offers a cloud-based lending platform powered by AI models. This technology helps banks lower costs, improve risk assessment, and generate more loans.

The stock collapsed 84% last year as growth came to a halt. A perfect storm of higher interest rates, the withdrawal of Federal stimulus, and economic uncertainty caused lenders to pull back on new loans. Upstart reported a decline in revenue of 67% year over year in the first quarter. 

Upstart generates all of its revenue from fees charged to banks and other lending partners for using its technology, so it's understandable for Upstart to report lower revenue when banks are being more cautious with lending. But as a long-term investor, the volatility in the share price is just the price of admission to get in on a potentially very rewarding investment.

For example, Upstart saw its revenue grow from less than $100 million in fiscal 2018 to $849 million in fiscal 2021. That is very rapid growth. Obviously, it won't always grow that fast, especially as it becomes a bigger business. But there are a few reasons investors should expect more growth, and most importantly, for Upstart to survive these hard times.

First, Upstart's AI models got more accurate over the last year. This will help the company sign up more lenders to use its platform and position for more growth once the market recovers.

Another reason to expect more growth is there are now more dealerships under contract to use Upstart's platform. Specifically, management said during the fourth-quarter earnings call there were 90% more dealers under contract than a year ago, which dovetails with the increasing accuracy of its AI models. 

Also, Upstart is showing progress to keep the business profitable, which is the single most important thing it can do this year. During the first-quarter earnings call, CEO David Girouard said the steps they have taken to reduce costs and become more efficient sets the business up "to return to profitable growth soon."

Overall, the company continued to strengthen its operations and should be stronger for it down the road. The stock soared 33% following its first-quarter earnings report, but more gains are in store for long-term shareholders as Upstart continues to improve its AI models and sign more contracts with lending partners.