Growth stocks experience varying degrees of interest from investors, depending on how the economy is doing. But even when interest ebbs, if the stocks represent solid businesses with long-term trajectories, the interest eventually returns as the company adjusts to meet changing needs.

With some recent changes in the economy, interest in growth stocks is back on the rise. If you have available cash to invest, there are several quality stock buys ripe for the picking. Here are two such growth stocks that could be excellent additions to a long-term investment portfolio right now.

1. Vertex Pharmaceuticals

Vertex Pharmaceuticals (VRTX -0.46%) is looking toward a brighter future in the next few years as it is on the cusp of multiple approvals with disruptive potential in numerous disease areas. Vertex is already known for its cystic fibrosis medications and is the only company with approved drugs on the market that treat the underlying cause of cystic fibrosis.

These drugs, called CFTR (cystic fibrosis transmembrane conductance regulator) modulators, brought in revenue just shy of $10 billion for Vertex in 2023. Still, Vertex estimates that thousands of additional patients across the globe could benefit from its existing therapies and aren't yet taking them. Vertex management also said there is an extensive addressable market of patients who could be prime candidates for its upcoming cystic fibrosis therapies.

Vertex is awaiting regulatory approval for a new triple-combination cystic fibrosis therapy, as well as a drug designed to treat moderate-to-severe acute pain ailments. That latter candidate is called suzetrigine, and it could usher in a new standard of care for pain management by providing effective relief without the addictive qualities of opioids.

The existing pain management market represents an addressable space in the ballpark of $115 billion globally, and some analysts think that, if approved, suzetrigine could add $1.4 billion to Vertex's top line annually by 2030. Suzetrigine is also being studied as a pain relief option for diabetic peripheral neuropathy, an ailment that impacts roughly 50% of diabetes patients at some point in their lifetime.

Meanwhile, Vertex is in the process of rolling out its gene-editing therapy Casgevy, the first CRISPR therapy ever approved and one that serves as a functional cure for two rare blood disorders. The company is also developing a stem-cell therapy that could be a cure for Type 1 diabetes.

Its existing therapies have brought in steady revenue, profits, and cash through the years (the company closed the recent quarter with $10 billion in cash and investments on hand), but its long-term growth story could be just getting started. Now could be a good time for investors to take a position or add to one in this top healthcare stock.

2. Netflix

Netflix (NFLX -1.80%) had a tough few years following the height of its pandemic successes, but the streaming giant appears to be back on track. Revenue is growing steadily, the company is consistently profitable again, and subscription growth remains at healthy double-digit percentage levels. Netflix has made some notable changes in recent years to propel its growth story after the post-pandemic doldrums.

One of the most notable changes to Netflix's business model has been the introduction of an ad-based tier. In addition, it's also cracked down heavily on password sharing. While these moves seemed risky, they appear to be paying off. Limiting the ability of multiple users from multiple households to share a single account and push them to create their own was a strategy that some were unsure Netflix could pull off. However, it looks like this strategy, combined with the introduction of a cheaper ad-based tier, has been wildly effective.

According to a study conducted by Antenna in 2023, shortly after Netflix announced that it would crack down on password sharing, Netflix achieved the four largest days of user acquisition in the U.S. since the market data platform began tracking the streaming service. The Antenna study found that Netflix achieved a 102% increase in average daily signups from the prior 60-day average.

Fast forward to the recent quarter (Q2 of fiscal 2024), and Netflix saw global paid streaming memberships rise 16.5% from the prior year period to 277.65 million. Revenue for the three-month period totaled $9.6 billion, a 16.8% year-over-year increase, while net income jumped 44% to $2.1 billion. It also achieved free cash flow of $1.2 billion in the quarter.

Management has said that the company will stop reporting subscriber numbers as of the first quarter of 2025, but its other financial metrics will provide valuable, if not more accurate, insight into the company's growth story. This is particularly true as Netflix continues to lean into its ad business. Netflix's ad tier membership grew 34% sequentially in the most recent quarter, and management is planning to launch an in-house ad tech platform in 2025 that will begin testing in Canada this year.

Netflix has seen shares skyrocket around 86% from just 12 months ago. The company's calculated changes to its business, which continue to diversify its revenue structure, and its underlying financial strength have been key needle movers here. Netflix also remains the leading streaming service globally despite rampant competition. Given the long-term potential of its ad business as well as its core business in the years ahead and the continued expansion of the global streaming market, it's not too late to capitalize on Netflix's growth trajectory as a shareholder.