In just a matter of weeks, the coronavirus disease 2019 (COVID-19) pandemic wreaked unprecedented havoc on the U.S. economy and labor market. Prior to the coronavirus, the U.S. unemployment rate was near a 50-year low (below 4%), while the economy was riding its longest expansionary streak in recorded history. But over the past seven weeks, some 33 million Americans have lost their jobs and nonessential economic activity has ground to a halt.

Though mitigation measures to slow disease transmission were necessary, the federal government knew exactly what sort of damage these actions would entail. That's why, on March 27, Congress passed and President Trump signed the Coronavirus Aid, Relief, and Economic Security (CARES) Act into law. This $2.2 trillion relief package set aside money for hospitals, small business loans, distressed industries, the unemployment benefits program, and most importantly 175 million Americans.

A messy pile of one hundred dollar bills and a U.S. Treasury check next to the Capitol building.

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A big stimulus check may be headed your way

The most widely known aspect of the CARES Act is the $300 billion apportioned as a direct stimulus to working Americans, families, and seniors. While not everyone will qualify for an Economic Impact Payment, as this stimulus money is officially known, the vast majority of adults will receive a payout, with many likely to receive the maximum of $1,200 per individual taxpayer and $2,400 for married couples filing jointly.

To qualify for this maximum payout, a single, married, or head-of-household filer simply needs to have earned less than $75,000, $150,000, and $112,500 in respective adjusted gross income (AGI) in their most recent tax filing (either the 2018 or 2019 tax year). Folks earning more than this will face a reduced payout, or no payout at all, depending on their AGI.

While a good portion of Americans plan to use their stimulus payouts to buy essential items or pay bills, some folks -- typically in the neighborhood of 10%, according to most surveys -- would rather invest their Economic Impact Payment. Having previously covered the stocks that I believe single filers should purchase with their $1,200 stimulus checks, here are three top stocks to buy for married couples who are in line to receive a $2,400 stimulus payout.

A surgeon holding a one dollar bill with surgical forceps.

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Intuitive Surgical

Among healthcare stocks, there's not one that has more surefire growth prospects, in my view, than robotic surgical systems developer Intuitive Surgical (NASDAQ:ISRG).

At the end of March, Intuitive Surgical had 5,669 of its da Vinci surgical systems installed worldwide. That's a pretty impressive ramp-up in the company's installed base over the past two decades, and it's light years ahead of the company's competition. Having the premier surgical system makes it highly unlikely that clients purchasing the da Vinci system will ever switch to a competitor (assuming the $0.5 million to $2.5 million per system price tag wasn't enough to compel loyalty). 

Even more important, Intuitive Surgical's business model is built in such a way that operating margins keep getting better over time. Selling or leasing its da Vinci system is just the first step in the process, and it's generally a low-margin step. That's because these systems are highly intricate and costly to build. Where Intuitive Surgical generates the bulk of its growth and juicy margins is from selling instruments and accessories with each procedure, as well as in servicing its machines for clients. As the company's installed base of systems grows, the percentage of sales derived from these higher margin segments will dwarf systems revenue, pushing operating margins higher.

Currently, Intuitive Surgical's da Vinci system is a leader in gynecology and urology surgeries, but has just scratched the surface in colorectal, thoracic, and other soft tissue applications. In my mind, this makes a double-digit growth rate sustainable for a long time to come.

A hacker wearing gloves who's typing on a keyboard in a dark room.

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Palo Alto Networks

Another top stock to buy for married couples with $2,400 in stimulus money is cybersecurity company Palo Alto Networks (NYSE:PANW).

Although technology is traditionally a cyclical sector -- i.e., it tends to do well when the economy is expanding and struggles when it's contracting -- Palo Alto moves beyond conventional rules. That's because the security protection provided by Palo Alto isn't optional. Regardless of business size or how well or poorly the economy is performing, cybersecurity solutions remain necessary in all environments.

Furthermore, Palo Alto is beginning to move away from its reliance on hardware security solutions and is, instead, focusing on higher margin subscription services. The thing about subscription revenue is that it's highly predictable and it allows a company like Palo Alto to plot its capital spending with utmost transparency. Through the first six months of fiscal 2020, higher margin subscription and support sales totaled 69.9% of the company's $1.59 billion in sales, up from 62.5% of the $1.37 billion in sales reported in the same period last year. 

This is also a company that has an exceptionally long growth runway when it comes to securing enterprise cloud systems. Palo Alto has made it clear to investors that it plans to spend aggressively to gobble up additional cloud security market share, and within the past couple of weeks it closed on its $420 million acquisition of CloudGenix. Expect this combination of organic innovation and piecemeal acquisitions to drive cloud-based cybersecurity market share. 

A cloud in the middle of a data center that's connected wirelessly to a number of devices.

Image source: Getty Images.

Amazon

Finally, stimulus payout recipients can't go wrong by choosing to buy the most dominant name in the e-commerce space, Amazon (NASDAQ:AMZN).

Amid the coronavirus pandemic, Amazon has been one of the few winners that's not in the healthcare space. Most retail stocks have seen their sales drop off big-time; but not Amazon. The company responsible for an estimated 38% of e-commerce in the U.S. has become an even more integral source for consumers as people stay at home and isolate.

It also doesn't hurt that Amazon has built up its Prime membership to more than 150 million people around the world. Since retail margins aren't anything worth writing home about, Prime membership fees help buffer against weak retail margins and help Amazon provide consistently cheaper pricing on goods than most brick-and-mortar retailers. Also, Prime does an excellent job of keeping Amazon members within its ecosystem of products and streaming content.

But the most exceptional growth driver here is Amazon's cloud service, Amazon Web Services (AWS). After accounting for "only" 11% of total sales in all of 2018, AWS was responsible for 13.5% of Amazon's total revenue in the first quarter. This is important because cloud-service margins make Amazon's other segment margins look like peanuts. As AWS grows into a larger percentage of total sales, Amazon should see its cash flow explode higher.