This is an awfully scary time to be a growth stock investor. It seems like hardly a day goes by when the most popular stocks don't move by 5% or more. Those moves have been to the downside so often that some of the best-performing stocks of 2020 and 2021 have lost over half their value. 

When individual stocks are severely beaten down, there's usually a specific reason. During bear markets like these, great businesses with large market opportunities can get dragged down, too, even when their underlying fundamentals are strong. 

These innovative businesses are doing a lot better than their dismal stock charts suggest. Now that they're down, just $500 is more than enough to start a position in one or both of these top growth stocks. 

Matterport

Not everyone is excited to put on virtual reality goggles so they can work or play in the metaverse. Matterport (MTTR 0.86%) is my favorite metaverse stock right now because it can succeed even if Mark Zuckerberg's ideas about the future of interpersonal interactions don't pan out.

Matterport helps its subscribers generate and maintain digital versions of physical locations. Free subscribers who are flocking to the service can use a handheld smartphone to create relatively simple versions of their storefronts, conference rooms, and factory floors. At the end of the first quarter, there were 504,000 free subscribers, a 79% gain year over year.

Matterport lets free subscribers maintain a single active space, and it's been able to convert a large portion of them to premium subscription packages, including more than one in five members of the Fortune 1,000. There were 58,000 paid subscriptions at the end of March, an 18% gain over the previous year.

So far, Matterport has captured 7.3 million spaces, which is just a tiny drop in the bucket of its total addressable market. There are an estimated 20 billion spaces around the world, and less than 0.1% have corresponding 3D digital maps. With a strong lead on any potential competitors, this company could quite feasibly retain a leading share of this market for many years to come.

Inari Medical

Inari Medical (NARI -0.29%) is a niche healthcare company that manufactures venous blood clot removal devices. FlowTriever for pulmonary embolisms and ClotTriever for deep vein thrombosis are minimally invasive catheters that physically remove life-threatening blood clots.

This is an outstanding stock to buy now and hold for the long run because there aren't any competitors marketing similar devices yet. Traditional clot removal techniques involve blood thinners and lots of observation in an intensive care unit. Treating patients with an Inari Medical device can make a big difference in a hospital's budget because it can remove clot burdens in a single session and safely get patients on their feet faster.

Healthcare providers are flocking to Inari Medical to get their hands on more of its catheters. Revenue soared 51% year over year to $87 million during the first three months of 2022. Management expects a minor sales growth deceleration in 2022, but years of double-digit growth ahead isn't a difficult picture to paint. Regarding the types of clots that Inari devices have U.S. Food and Drug Administration clearance to treat, less than a third of interventions are performed with the company's devices.

If you include addressable clots currently treated with more conservative means, Inari has barely scraped the surface of its total addressable market. Considering the company has plenty of room to grow, and a lack of competing devices, a small investment in this stock could make a big difference for your portfolio down the line.