There's no guaranteed way of building wealth in today's market, but consistently investing extra cash in great companies with rock-solid businesses can improve the odds that you achieve your long-term financial goals. It takes patience, dedication, and habitual investing to build a winning portfolio.

As you build that portfolio, it's important to remember that not all of your stocks will be winners, and no investment is a surefire moneymaker. That said, when you buy businesses you understand inside and out, with strong competitive advantages, excellent financials and leadership, and durable value propositions, you can add to those types of stocks again and again, compounding your returns with time.

If you're looking for two impressive growth stocks to add to your portfolio as 2024 kicks off, don't miss these worthy contenders when you hit the buy button.

1. Vertex Pharmaceuticals

Vertex Pharmaceuticals (VRTX -0.06%) has gone from strength to strength lately, on the heels of a continued stream of profits from its portfolio of blockbuster products and a new approval that could change the face of the fight against two potentially life-threatening blood disorders. The company focuses on diseases that have been historically underserved by the medical community at large.

The company's current portfolio revolves around four cystic fibrosis medicines, all of which belong to a class of drugs called CFTR modulators. These four drugs are the only ones that have been commercialized to date that treat the underlying cause of cystic fibrosis, so demand for Vertex's products is not only high but consistent. These medications generally require two doses daily, and are an essential part of patients' lives.

Vertex's top-selling drug is Trikafta, which at the time of its approval by the U.S. Food and Drug Administration in 2019 covered roughly 90% of all cystic fibrosis patients in the U.S. This drug brought in $6.6 billion in revenue in the first nine months of 2023 alone, out of Vertex's total revenue for that period of $7.4 billion. And despite the market-leading success of Vertex's cystic fibrosis drug franchise, management has said that there are over 20,000 eligible patients in North America, Europe, and Australia who could benefit from these medicines but aren't taking them yet.

Vertex is working on building out a portfolio that spans many rare disease drug areas, with the latest move on that front being the approval of its gene-editing therapy Casgevy (also known as exa-cel). Casgevy is designed to serve as a one-time functional cure for both sickle cell disease (SCD) and transfusion-dependent beta thalassemia (TDT). Both of these diseases are characterized by severe issues with a patient's hemoglobin and require regular blood transfusions. Not only can these blood disorders cause significant pain for patients, but both can lead to a host of other dangerous and potentially deadly physical complications.

Casgevy was developed in partnership with CRISPR Therapeutics and became the first-ever gene editing therapy to garner regulatory approval. The therapy is made by taking the patient's own blood stem cells, editing them to produce elevated levels of fetal hemoglobin, and infusing them back into the patient. Patients must undergo chemotherapy to prep or condition their cells for the therapy, and a lengthy recovery process. Casgevy has been approved for qualifying patients with SCD and TDT in the U.S., U.K., and Saudi Arabia, and is currently pending approval in the E.U., which recently recommended conditional authorization for both indications.

One of multiple promising pipeline candidates that current and prospective Vertex investors should watch is VX-548, the company's non-opioid treatment for various acute pain ailments. The treatment just garnered positive results in a phase 2 study for use in patients who suffer from diabetic peripheral neuropathy, a condition that affects roughly half of all diabetes patients at some point in their lives.

Vertex still looks to be in the very early stages of its growth story, with a runway of expansion ahead through existing and new therapies in its portfolio. Now may be a wise time to consider a position in Vertex Pharmaceuticals, which is already up 40% over the trailing 12 months, double the S&P 500's performance in that same period.

2. Etsy

Etsy (ETSY 0.34%) has gone through its fair share of struggles in a market that is tired of growth stocks in the aftermath of the worst of the pandemic, and where fears of a recession have pulled many businesses fueled by discretionary spending further downward. With the stock trading down by about 50% over the last 12 months alone, it's fair to say that it hasn't been an easy time to be an Etsy shareholder.

General market sentiment hasn't been the only reason behind Etsy's drop. The company has dealt with a notable slowdown in growth, bouts of unprofitability, and changes in both the numbers of active buyers and sellers on its platform in past quarters. While some of the unfavorable growth patterns derive from poor comparisons to heightened levels of growth at the peak of the pandemic, it's important to understand the backdrop that has fueled Etsy's performance in preceding quarters.

Etsy has undertaken multiple steps to drive operational efficiency. These include divesting its pandemic-era acquisition of the Brazilian e-commerce marketplace Elo7, and most recently, scaling back its team. Management announced these restructuring efforts on Dec. 13, the result of which will be an 11% shave to its workforce.

While news of this kind is never positive, least of all for the people whom it directly impacts, these changes should drive operational improvements with time. The last few quarters have seen a number of positive developments on the financial front that investors shouldn't ignore either, particularly when viewed against the backdrop of prior periods of growth instead of simply year-over-year comparisons.

Let's consider the third quarter, Etsy's most recently reported financials. The company brought in $3 billion in gross merchandise sales (GMS) and $636 million in revenue, which represented respective increases of 1.2% and 7% from the same quarter in 2022. Etsy's net income was down more than 100% from what it reported in the year-ago period, but it still generated generally accepted accounting principles (GAAP) profits to the tune of approximately $88 million. Finally, Etsy reported 8.8 million active sellers and 97 million active buyers in the third quarter of 2023, up 19% and 3%, respectively, from the prior year.

Now, let's look at how those figures compare to the third quarter of 2020. Those GMS and revenue figures are up approximately 15% and 40% on a three-year basis, respectively, while net income is just behind what Etsy reported in that quarter three years ago ($92 million). And, those active seller and active buyer figures represent increases of around 140% and 40%, respectively, compared to the third quarter of 2020.

Etsy may have a bumpy road ahead, but the growth story remains as the company continues to make strides in a highly underpenetrated segment of the broader e-commerce market. The case for this stock and its namesake marketplace -- which remains a leader in the area of vintage, handmade, and specialty items -- could drive more risk-averse investors to buy this top growth stock on the dip.