It's official: The S&P 500 is now in a new bull market. Last week, the major index set a record high. This was the only prerequisite remaining for the S&P to enter bull market territory.

Bull markets present fantastic buying opportunities for investors. But which opportunities especially stand out? Here are three no-brainer stocks to buy hand over fist.

1. D.R. Horton

You can rest assured that the bull market won't leave D.R. Horton (DHI -2.12%) behind. Shares of the big homebuilder have soared more than 60% over the last 12 months and that momentum seems likely to continue.

D.R. Horton ranks as the largest homebuilder in the U.S. based on volume. That's a perch it's held since 2002. The Texas-based company operates in 118 markets spanning 33 states.

There's an ongoing housing shortage in the U.S. The only solution to it is for more houses to be built. D.R. Horton is playing a key role in helping solve the problem. The company closed on more than 89,000 new homes in its last fiscal year, which ended on Sept. 30, 2023.

If the Fed cuts interest rates this year, as many believe it will, that would provide a nice tailwind for D.R. Horton. Lower interest rates lead to lower mortgage rates, which in turn boosts new home starts.

Also, despite its impressive gains and great prospects, the stock remains cheap. D.R. Horton's forward price-to-earnings ratio is only round 12.

2. Meta Platforms

Few stocks have been bigger winners since early 2023 than Meta Platforms (META 2.16%). Shares of the social media giant have skyrocketed close to 175% over the last 12 months. Wall Street doesn't seem to think that Meta has much more room to run with its current share price nearly at the average price target. However, I think that Meta could surprise analysts.

The company remains a huge force in the advertising world. Nearly 4 billion people across the world use its Facebook, Instagram, Messenger, and WhatsApp apps each month. That's a lot of eyeballs that advertisers can target in ways that linear TV and print media can't touch.

Importantly, Meta's bottom line is improving significantly after a tumultuous period. The company's earnings vaulted 164% higher year over year in the third quarter of 2023. This impressive jump is largely due to Meta's renewed focus on profitability.

Artificial intelligence (AI) presents a massive growth opportunity for Meta. CEO Mark Zuckerberg recently posted on Instagram Reels that AI will be the company's "biggest investment area in 2024." He revealed that Meta is actively working on developing "general intelligence" -- a reference to what is often called artificial general intelligence (AGI), which would be capable of thinking and reasoning as humans do. The company's deep pockets and its open-source approach could make it a formidable player in the AGI race.

3. Vertex Pharmaceuticals

Vertex Pharmaceuticals (VRTX -0.20%) has done something most stocks haven't: deliver big gains when the overall stock market plunged in 2022 and when it soared in 2023. Over the last 12 months, the biotech stock is up more than 40%. I suspect Vertex will keep up its winning ways.

The company recently won U.S. Food and Drug Administration approvals for Casgevy in treating sickle cell disease and transfusion-dependent beta-thalassemia. Casgevy is the first CRISPR gene-editing therapy to make it to market. Vertex and its partner CRISPR Therapeutics should rake in billions of dollars in sales from it over the next few years.

Two other new drugs could be on the way shortly. Vertex plans to soon announce results from late-stage studies of its vanzacaftor/tezacaftor/deutivacaftor combination therapy in treating cystic fibrosis (CF) and VX-548 in treating acute pain. The vanzacaftor triple-drug combo seems likely to become the company's most profitable CF therapy so far. VX-548 has huge commercial potential as a painkiller that doesn't have the addictive characteristics and side effects of opioid drugs.

Vertex is also evaluating inaxaplin in a pivotal clinical study targeting APOL1-mediated kidney disease (AMKD). If all goes well, inaxaplin could become the first approved therapy for treating the underlying cause of AMKD. The company has a lot of potential.