Cryptocurrencies made a splash at the Super Bowl. Four ads touting cryptocurrencies aired during the three-and-a-half hour broadcast. While that's not a large number, it's still a sign that cryptocurrencies have gone mainstream.The ads ranged from one showing an older LeBron James going back in time to visit his younger self, to one where comedian Larry David misses out on every major innovation throughout history and now, of course, resists crypto, too. The one that got the most attention featured a QR code floating across the screen with background music for 60 seconds. It confused many people, but many others scanned the codes on their screens with their phones.They were led to a promotion for $15 worth of free Bitcoin to sign up on Coinbase, a cryptocurrency exchange, where people can buy and sell the virtual currency. But the site crashed from the massive surge in traffic, which led to the inevitable flurry on social media. Cryptocurrencies are a form of digital currencies built on blockchain technology, using a public distributed ledger that keeps track of every transaction. They are decentralized and not connected to any third party like a bank. The growth of cryptocurrency has been primarily as an investment, not as a medium of exchange. But cryptocurrencies are wildly volatile and can have over 10% swings in price in a single day. Last year, a crypto called Dogecoin rose by about 15,000% and then quickly fell spectacularly in value. These big moves have attracted millions of investors. A study done by Grayscale Investments, found that more than half (55%) of investors who currently own Bitcoin began investing in them just over the last 12 months.A study done by the Pew Research Center found that 16% of Americans have either invested, traded or used cryptocurrencies such as Bitcoin and Ethereum. "More investors see long-term value in adding Bitcoin and digital currencies to their investment portfolios," said Michael Sonnenshein, CEO of Grayscale Investments. Super Bowl ads tend to be some of the most coveted spots on network television. This year a 30 second Super Bowl spot sold for $6.5 million according to NBC. Last year commercials averaged $5.6 million on CBS. This crypto ad craze is reminiscent of the 2000 Super Bowl during the dot com era. One company, pets.com, had an ad campaign featuring a sock puppet mascot who would later be interviewed by People magazine. Some investors believe cryptocurrencies are bound for a similar crash and shakeout like the dot com companies. Charlie Munger, the billionaire vice chairman of Berkshire Hathaway, told the Sydney Morning Herald of cryptocurrencies: "I wish they'd never been invented." But cryptocurrency has a lot of believers too, including the TV-famous billionaire investor Mark Cuban, who says 80% of his investments are in cryptocurrencies. Copyright 2022 NPR. To see more, visit https://www.npr.org.