Buying and selling stocks throughout the day may seem like fun until you realize just how easy it is to lose money. And if that's your day job, you can imagine just how stressful it might be not knowing how much you might make in a given week or month. Day trading isn't for everyone, and even though it might appear lucrative now while the markets are strong, a downturn could quickly change that perception.

Investors like Warren Buffett have gotten rich from long-term investing, not by speculating on short-term stock patterns. If you want to avoid the headache and worries that come with obsessing over a stock, two investments that could be great options for your portfolio today are Eli Lilly (NYSE:LLY) and Facebook (NASDAQ:FB). In the past five years, their share prices have soared by more than 130%, outperforming the S&P 500 and its 91% gains during that time by wide margins. Here's why they are still great buys today. 

Team of traders working in an office.

Image source: Getty Images.

1. Eli Lilly

Eli Lilly is a solid long-term investment because it manufactures drugs that many patients literally can't live without. Even though COVID-19 is making it more challenging for patients to visit the doctor's office, the company's business and its products are proving to be resilient. On Jan. 29, Eli Lilly released its fourth-quarter numbers. Sales of $7.4 billion for the quarter ending Dec. 31, 2020 were up 22% from the same period last year. And for the full year, revenue of $24.5 billion grew 10% from 2019.

A key reason for the improved sales in Q4 was the company's monoclonal antibody treatment for COVID-19, bamlanivimab, which generated $871.2 million during the period. But even without the treatment, Eli Lilly's sales would still have have grown by 7% during the quarter. In November 2020, the U.S. Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for bamlanivimab for patients with mild to moderate COVID-19. And with coronavirus cases still on the rise, Eli Lilly is likely to continue to benefit from the use of the treatment.

The company normally records strong gross margins of close to 80%, so any increase in sales is going to help bolster its bottom line.  Over the past four quarters, 20% or more of its revenue has flowed through to net income. In Q4, the company's profit of $2.1 billion was 42% higher than in the prior-year period.

On top of an already strong business, which includes top diabetes drug Trulicity, which generated $5.1 billion in revenue in 2020, bamlanivimab could make this year a particularly strong one for Eli Lilly. And in addition to any gains investors make from the stock in 2021, those who buy the stock today will also see their portfolio rise in value due to the company's dividend. With a yield of around 1.6%, Eli Lilly's payouts are in line with what you can typically earn from the average stock on the S&P 500.

This healthcare stock, with its recession-proof line up of drugs and strong financials, is a great option to hold on to for the long term.

2. Facebook

Love or hate Facebook, there's no denying the social media company's popularity. On Jan. 27, Facebook released its fourth-quarter results, and as of Dec. 31, 2020, it reported monthly active users of 2.8 billion, up 12% from a year ago. Sales in Q4 totaled $28.1 billion and were up 33% year over year while net income of $11.2 billion grew by 53%. The company's earnings, revenue, and user numbers all came in above analyst expectations. 

Facebook, did, however, warn that there are some question marks ahead from an "evolving regulatory landscape" and changes coming to Apple's iOS 14 that will require app developers to ask the user for greater permissions. At this point, it's too early to tell how much these developments might impact Facebook's numbers.

There is the possibility that the federal government will try to break up the company's business due to antitrust issues, which could include undoing its acquisitions of Instagram and WhatsApp. But sorting out all these issues could take years, and adversity isn't new to the company. This is a company that's still doing well and remains popular despite the Cambridge Analytica scandal of a few years ago, when Facebook improperly shared data on up to 87 million users. Potentially losing WhatsApp or Instagram would be a blow to Facebook's business, but that doesn't mean it wouldn't be able to find ways to adapt. 

Although there is an uncertain road ahead for the company, I don't think it's enough to deter investors today. With billions of users on one of its platforms every month and profits continuing to flow in, this is still a growing and exciting business to invest in, and that's not likely to change anytime soon. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.