Non-fungible tokens (NFT) continue to grow in popularity as digital art from all around the internet sells for thousands of dollars.

Twitter CEO Jack Dorsey is looking to sell the very first tweet, which was made by himself, and it has already broken into the millions at an ongoing auction. 

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Dorsey shared a link to a website known as Valuables, which lets people auction off tweets as NFTs. 

The current highest bid, $2.5 million, was made by the CEO of Bridge Oracle, Sina Estavi, who is apparently very interested in owning the simple but historic five-word tweet.

This is not the first piece of internet history that will sell for a ridiculous amount of money, as NBC reports a digital rendition of the popular 2011 meme Nyan Cat sold as a NFT for nearly $600,000 at an auction. 

NFTs can be looked at as a form of online art trading, but with each piece being completely digital.

But why buy something that you could simply screenshot or download? Well simply put, there's no money in just taking a cool picture off the internet.

NPR reports that when you purchase a NFT, you get a form of barcode that can act as a sort of certificate of authenticity, meaning you will have proof that you own an original piece of work, much like buying da Vinci's "Mona Lisa" or Van Gogh's "Starry Night" but without the physical aspect.

Like old paintings, these digital works of art have the ability the gain value throughout time, meaning a NFT can be considered an investment opportunity.