Growth stocks have fallen out of favor over the past month; many have dropped noticeably off highs, and investors are trying to figure out when there might be a rebound. But when things seem dark, winners often lead the comeback and take the market higher.

These two stocks have been big winners since the pandemic lows in March 2020 and still have the growth and the fundamentals to continue pushing higher. They could power the market's next bull run.

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Block

Money and how it moves between consumers and businesses is changing, and fintech company Block (SQ -0.46%) (formerly Square) is at the forefront of this evolution. Its point-of-sale (POS) terminals and software have empowered small businesses to accept digital payments more easily than ever, while its Cash App ecosystem is disrupting the traditional relationship between consumer and bank.

Banks have been around for centuries and are built with outdated "DNA," so to speak. They have physical branch locations that are expensive to operate and are slow to adopt change. The average bank spends a lot of money to acquire a new customer -- the amount can range as high as $1,500 to $2,000.

Block is a digital business model; users need only download Cash App on their phones to access all of its features. The company can acquire customers for as little as $5, giving it a significant financial advantage over brick-and-mortar banks.

The company tracks gross profit growth as its primary indicator of how the business is performing because Bitcoin trades on Cash App can distort revenue growth numbers. In third-quarter 2021, Block's gross profit grew 43% year over year to $1.13 billion, with the POS ecosystem and Cash App contributing nearly equal amounts.

Cash App could become Block's primary business over the years to come; it recently opened up to teens in the U.S. aged 13-17, a demographic of roughly 20 million. Cash App is also aggressively marketed to millennials in an attempt to build a money relationship with individuals earlier on, so that it can pay off when they enter their prime earning years.

Block is acquiring Afterpay, a Buy Now, Pay Later (BNPL) company, for $29 billion in stock to add as a function for Cash App users. It's another tool that could draw young users into the Cash App ecosystem. BNPL is a rapidly growing segment in consumer credit that could grow an estimated 15-fold from its current size by 2025.

Block's stock is trading down near 52-week lows of $180, down more than 30% from its highs. The stock's price-to-sales (P/S) ratio is just over 5, its lowest since the height of the pandemic. However, I think this $78-billion market cap company is still fundamentally sound and successful enough to help power the indexes if it goes on a run.

Sea Limited

People in Southeast Asia are among the most internet-savvy globally, which has made it a goldmine for Singapore-based internet company Sea Limited (SE 3.59%). The company operates a three-headed business model that includes gaming, e-commerce, and fintech segments.

Sea has grown revenue at an average of 71% per year over the past five years, driven by a Southeast Asia customer base of 670 million people who are young (50% of the population under 30) and spend an average of eight hours per day connected online.

Its gaming segment created Freefire, one of the most popular mobile games in the world, and is the company's primary cash cow. In Sea's 2021 third quarter, the game brought in almost $1.1 billion in revenue, and $715 million of that turned into EBITDA (earnings before interest, taxes, depreciation, and amortization). The profitability of the gaming business helps fund investments in the non-profitable e-commerce and fintech segments.

Investing its gaming profits into the business has enabled Sea Limited to aggressively expand into new markets like Latin America, Poland, and India. Freefire is also a great wedge; its popularity in these new markets helps Sea tie its e-commerce business to ads and promotions to gain customer traction.

During the pandemic, Sea has been a massive winner, soaring from nearly $50 to as high as $372 before the recent pullback brought shares back down to around $222. Sea is just beginning to gain traction in these new markets, so the company could see continued great revenue growth for the foreseeable future. The stock has a market cap of $123 billion, hence why I believe Sea's strong growth could help push the market higher when it reaches new highs of its own.