The S&P 500 last month confirmed what investors had been hoping for: A bull market has arrived. In fact, this fantastic phase of market expansion has been in place since the index started recovering from its bear-market low back in October 2022. To confirm a bull market, the index must reach a new record high, which means that bull markets are generally declared well after they've started.

But don't worry -- there's still plenty of time to benefit from this time of market growth, because history shows us bull markets typically last for years. So, how exactly can you boost your portfolio's performance during a bull market? You can invest in growth stocks, which tend to thrive in markets favoring expansion and in periods of economic recovery or growth.

Let's check out two growth stocks to buy hand over fist in the new bull market.

Two scientists smile as they work on something in a lab.

Image source: Getty Images.

Iovance Biotherapeutics

Iovance Biotherapeutics (IOVA 0.87%) has reached an exciting point in its growth story. Regulators are reviewing the company's lead product, lifileucel for advanced melanoma, and are set to issue a decision on or before Feb. 24. The drug could bring in global sales of as much as $959 million in 2029, according to GlobalData.

If the U.S. Food and Drug Administration (FDA) offers Iovance a regulatory nod, revenue could start rolling in relatively soon. The company says about 50 authorized treatment centers should be ready for action within 90 days of the regulatory decision deadline. And Iovance expects "rapid uptake" of lifileucel, thanks to the company's early work to prepare the terrain of manufacturing, commercialization, and reimbursements.

Iovance's product could stand out due to the personalized way it helps address a patient's cancer. The company's technology is built on tumor-infiltrating lymphocytes (TILs), naturally occurring cells in the body that fight off cancer. But when cancer cells prevail, TILs aren't able to effectively fight back. That's where Iovance comes in. The company collects a patient's TILs, reinvigorates them, then administers them back to the patient.

And this could be just the beginning for Iovance, as the company's TIL therapy is involved in seven clinical trials across five tumor types.

Today, the shares trade for about $8 each, considerably lower than they were a few years ago, when Iovance was much farther from commercializing a product. Of course, risk remains because an FDA approval isn't guaranteed. But if you're an investor comfortable with this risk, Iovance makes a top bull-market buy for its explosive growth potential.

Intellia Therapeutics

Intellia Therapeutics (NTLA 3.70%) specializes in the innovative field of gene editing, correcting faulty genes responsible for disease. The company uses the CRISPR technique, which involves cutting DNA at a particular location and allowing a natural repair process to take place.

Intellia is likely to benefit not only from its own pipeline progress, but also from recent good news in the CRISPR gene-editing space. Its peer CRISPR Therapeutics recently won the world's first regulatory authorization for a product based on the CRISPR technique. This shows that regulators are ready to approve products using this new technology, as long as clinical data support the case. (And CRISPR Therapeutics isn't a direct competitor since its product and candidates treat different illnesses.)

As for Intellia itself, it's heading toward some key moments. The company's main priorities through 2026 include the completion of a phase 3 study on, and requesting regulatory approval for, its treatment of hereditary angioedema, as well as completing enrollment in a pivotal study of a treatment for transthyretin amyloidosis (ATTR). Hereditary angioedema involves severe, unpredictable swelling, while ATTR affects various organs including the heart.

Meanwhile, any positive data from these studies could lift the shares, which are trading considerably lower than their peak a few years ago. I also like the fact that Intellia has around $1 billion in cash, giving it a cash runway through mid-2026.

If you're looking for a stock that has what it takes to soar in this new bull market, you may want to buy shares of this gene-editing innovator hand over fist.