Wondering what to do with your stimulus check? Or, have you saved up money for a foray into the stock market? Putting $5,000 into a group of stocks can diversify your portfolio, offering you greater security in addition to what you're really looking for: high gains.

Target (NYSE:TGT), Etsy (NASDAQ:ETSY), and Amazon (NASDAQ:AMZN) are great companies that have delivered fabulous gains over time and still offer the opportunity for high growth.

Where you can get everything

If you live in the U.S. and have never been inside a Target store, you're an anomaly. The cheap and chic retailer operates nearly 1,900 stores in 50 states and took in $22 billion in sales in the 2020 third quarter. As an essentials retailer, Target was allowed to remain open during the pandemic, and sales soared by double digits every quarter during the crisis. In the third quarter ended Oct. 31, comps increased 21%, fueled by same-day shopping options. Target had already been a leader in omnichannel shopping for years before the coronavirus pandemic, and its many iterations of digital and physical shopping proved to be a crucial factor in its success over the past few months. In the third quarter, digital sales increased 155% and same-day services, which comprise pick up, drive up, and Shipt, grew 217%.

Target Shipt worker bringing a full cart to a car.

Image source: Target.

Target is also growing the bottom line, which increased 100% to $2.79 in the third quarter. It developed processes for handling orders through local stores, which lowers warehousing costs and makes for faster shipping. Seventy-five percent of digital orders, including all same-day pickup orders, are fulfilled in-store, and dedicated Shipt shoppers prepare same-day delivery orders.

Target also has many popular owned brands that are exclusive to its stores and are a key element in the company's discount fashion branding. The company has 52 stores in development, and there are still a lot of exciting growth opportunities in stores and brands.

Target stock gained 166% over the past three years. It's also the only stock on this list that pays a dividend, which yields 1.4%, providing income while the stock grows.

Custom, exclusive, and digital

Etsy has been around since 2005, but it really hit the mainstream during the pandemic when its handmade masks became a global sensation. But new buyers were drawn to the platform for everything from handmade soap to custom bed linens, and it's these buyers who are moving the company forward.

A man working on a computer in his woodshop.

Image source: Getty Images.

Gross merchandise volume increased 119% in the third quarter ended Sept. 30, and revenue grew 128%. Even better, the company is turning those sales into profits, and net income grew 520%.

Customers are coming, with a 112% increase in the third quarter, and they're turning into active buyers, which grew 56%.

But the growth is due to more than just masks. In the second quarter ended June 30, customers whose first purchase was not a face mask spent 50% more than new customers the prior year, while those who first bought masks continued buying masks.

Etsy is still in its infancy, with less than $500 million in third-quarter revenue. It's gaining new and loyal customers, and it has also expanded with the acquisition of Reverb, which sells musical instruments. It's launched new, customer-friendly features partnered with celebrities, influencers, and designers to create exclusive collections.

Etsy stock has gained more than 1,000% over the last three years. But don't worry, the train has barely left the station.

The largest digital store and still growing

If you've got $5,000, more than half of that would buy just one share of Amazon. But it's worth the price tag.

A woman opening a package in her kitchen.

Image source: Getty Images.

The king of e-commerce had a blowout holiday season, demonstrating that it's still the leader in digital shopping by far. Sales exceeded expectations, growing 44%, and income more than doubled.

But Amazon is a lot more than retail. Amazon Web Services has become an important element of the overall business, and contributes an oversized portion of profitability -- sales in the fourth quarter accounted for about 10% of total sales but more than half of operating income.

Amazon continues to disrupt various industries, such as prescription drugs with its recent launch of Amazon Pharmacy. It made strides in 2020 with its foray into physical grocery, and it developed partnerships to market its cashierless technology.

In other words, Amazon is far from finished. The stock gained 136% over the past three years, and investors can be confident that more gains are at hand.