Day trading is alive and well. With dozens of online brokers offering stock-trading services -- often free of charge -- anyone with an internet connection can look to make a fortune by taking advantage of daily swings in the prices of stocks. But this investment strategy is risky: No one knows when shares of a company will rise or drop, sometimes for no reason related to its fundamentals. This factor (and others) makes day trading an unreliable strategy. 

Instead, investors should focus on a proven method for generating wealth: Buying shares of great companies and holding them through thick and thin. Abbott Laboratories (ABT -0.65%) and Bristol Myers Squibb (BMY -2.21%) are two excellent candidates. Both of these healthcare companies boast strong lineups and solid growth prospects. Let's dig a little deeper into each company's respective business.

Doctor putting hundred dollar bills in his pocket.

Image source: Getty Images.

1. Abbott Laboratories

Abbott Laboratories ran into some trouble last year as sales of its medical devices fell because of the pandemic. However, the company was able to offset these declining sales by entering the COVID-19 testing market. Abbott Laboratories devised and launched several coronavirus testing kits, which had a massive impact on its financial results. 

In the first quarter ending March 31, the healthcare giant recorded revenue of $10.5 billion, which grew by 35.3% year over year and included $2.2 billion in coronavirus testing-related sales. The COVID-19 testing market will probably slow as vaccines for the disease become mainstream. 

Thankfully, Abbott Laboratories has other long-term growth drivers. Most notably, there is the company's diabetes care segment. Abbott Laboratories markets the Freestyle Libre, a continuous glucose monitoring (CGM) system. This franchise is important for the company's future because of the prevalence of diabetes, which has been growing steadily in the U.S. over the past several decades. In 1958, just 0.93% of the population was diabetic, but that metric had risen to a whopping 10% as of 2018. Further, that number is projected to keep growing. The need for innovative products that help diabetes patients manage their illness won't subside anytime soon.

CGM systems such as the Freestyle Libre allow these patients to keep track of their blood glucose levels while significantly reducing (or eliminating) the need for pesky and painful finger sticks. According to Grand View Research, the CGM market will expand at a compound annual growth rate (CAGR) of 12.7% through 2027.

In the first quarter, Abbott Laboratories recorded $980 million from its diabetes care segment, a 30.2% year-over-year increase largely driven by its Freestyle Libre franchise. The company expects 10%-plus growth in its diabetes care business for the fiscal year.

Abbott Laboratories can also count on its MitraClip System -- one of the leading devices on the market for the treatment of a heart condition called mitral regurgitation -- for revenue and profit growth. Thanks to these products (and more), the healthcare company looks well-positioned to deliver strong financial results year after year, and its stock price should follow suit. 

Rolled up dollar bills stacked in a ladder pattern.

Image source: Getty Images.

2. Bristol Myers Squibb

Thanks to the groundbreaking medical innovations that have occurred over the past century, human beings now live longer than ever. But these longer lifespans also translate to higher spending on healthcare products, including prescription drugs. That's why pharma giant Bristol Myers Squibb, which develops lifesaving drugs, could be an excellent long-term play.

While the company's revenue continues to face headwinds due to the impact of the COVID-19 pandemic, Bristol Myers Squibb boasts a rich lineup of products, including more than half a dozen blockbuster medicines. These include multiple myeloma treatments Revlimid and Pomalyst, both of which Bristol Myers Squibb added to its arsenal via its November 2019 acquisition of Celgene in a cash-and-stock transaction valued at $74 billion.

In the first quarter ending March 31, sales of Revlimid came in at $2.9 billion, a 1% year-over-year increase. Meanwhile, the company reported $773 million in revenue from Pomalyst, 8% higher than the year-ago period. Other notable products in Bristol Myers Squibb's lineup include anticoagulant Eliquis. In the first quarter, the company's revenue from this medicine grew by 9% year over year to $2.9 billion. Then there is cancer drug Opdivo, whose sales during the first quarter declined by 3% to $1.7 billion.

The decrease was caused by lower demand for the drug, which was driven by increased competition, the COVID-19 pandemic, and other factors. Investors need not worry about this cancer medicine, however. Opdivo is still undergoing over a dozen trials. Last year alone, it scored seven new regulatory approvals. Management thinks that sales of Opdivo will start growing again this year.

The company's revenue during the first quarter only grew by 3% year over year, to $11.1 billion. Excluding the impact of the outbreak, it would have grown by 8%. Further, Bristol Myers Squibb has over 50 clinical compounds in development. Even a handful of approvals for these candidates every year -- which seems more than likely -- will help the company continually replenish its stock of medicines to keep its revenue and profits growing.

Though Bristol Myers Squibb has underperformed the market over the past 12 months, these factors will help its performance pick up, especially once the pandemic subsides. For investors willing to stay the course, this pharma stock looks like an excellent pick.