Today’s prevailing digital currency was worth just $12 in 2013, and has at times been dismissed as an internet fad favored by nefarious wheelers and dealers trying to circumvent taxes or the law.

Like it, love it, or confused by it, bitcoin and other cryptocurrencies have become impossible to ignore. Chicago’s two main exchanges, the Chicago Mercantile Exchange and the Chicago Board Options Exchange have announced plans to launch bitcoin futures contracts, and the U.S. Commodity Futures Trading Commission has already given them the green light. Nasdaq may be jumping into the bitcoin futures race as early as second quarter next year, Bloomberg reports. Bitcoin advocates are hoping the exchanges can help stabilize the highly volatile currency.

Cryptocurrencies provide a digital alternative to government-issued fiat currencies and can be used in online marketplaces to buy everything from a cupcakes to plane tickets to cyber pets. While bitcoin remains both inconveniently slow (transactions can take upwards of 10 minutes) and risky (buyers cannot set a price until the day of the transaction, leading to wide fluctuations), some say it’s already safer than certain foreign currencies, such as Venezuela’s bolívar.

That’s because Bitcoin is protected from fraud and counterfeit by technology called blockchain — an encrypted ledger system that records transactions accepted by consensus of asset managers. The Atlantic‘s Derek Thompson summarized bitcoin as a “frankly terrible currency built on top of a potential transformative technology,” one that could have the power to change our conventional understanding of money.

Others are more concerned by possible financial risks than potential benefits. Investing pioneer and Vanguard Group Inc. founder Jack Bogle reportedly advised avoiding bitcoin and “like the plague,” joining other investors in similar criticism. “There is nothing to support Bitcoin except the hope that you will sell it to someone for more than you paid for it,” Bogle said, according to Bloomberg.

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Despite the growing number of detractors warning of a bubble, bitcoin mania shows no sign of abating and its competitors are also gaining traction, all rushing to become the main purveyor of a future cashless world. Here’s the low-down on five of the most popular bitcoin rivals, all of which had a market value of over $5 billion Monday according to coinmarketcap.com.

Ethereum (ETH)

Like bitcoin, ether “tokens” are underwritten by a blockchain network, in this case called Ethereum. Pioneered by a former Bitcoin Monthly writer, Ethereum was launched in 2014 with an aim to pursue further decentralization. It differs from bitcoin primarily in application: Ethereum is an open, decentralized software platform where ether is used to pay for transaction fees and services. As of Monday, it was trading at a rate of more than $472 with a market cap of about $45.5 billion.

Ripple (XRP)

Launched in California by former bitcoin developers in 2012, Ripple is considered by some industry experts to be bitcoin’s logical successor, according to the New York Times. It’s already catching on among banks as a worldwide payment and remittance system. Unlike bitcoin, Ripple is not just a currency but a system through which any currency can be transferred or traded. The Times advised to think of it as a Western Union without the heavy fees. As of Monday, Ripple was trading at a rate of more than $0.25 with a market cap of around $9.82 billion.

IOTA (MIOTA)

IOTA, with the tagline “Next Generation Blockchain,” is one of the newest contenders in the increasingly crowded cryptocurrency field. Unlike its rivals, IOTA is not reliant on an underlying blockchain network, but uses an alternative, distributive ledger system called Tangle. Partnered with Microsoft, Fujitsu and several other companies, IOTA considers itself the first marketplace powered by the Internet of Things. As of Monday, it was trading at a rate of $2.43 with a market cap of around $6.75 billion.

Dash (DASH)

Dash ran through a ringer of names before settling its current epithet. There was XCoin (XCO), the original, in January 2014. Then there was the dubious-sounding Darkcoin. Then finally, there was “Digital Cash” and its portmanteau Dash. Dash differs from its competitors with a focus on privacy and anonymizing transactions, and by operating on a two-tired system: coin “miners” are are overseen by “masternodes,” a decentralized, volunteer network that signs the transactions. As of Monday, it was trading at a rate of $777 with a market cap of around $6 billion.

Litecoin (LTC)

The brainchild of a former Google employee, Litecoin has been called the silver to bitcoin’s gold, that is, a slightly cheaper, more readily available option. Litecoin was launched in 2011, as a faster alternative to bitcoin, processing a bloc every 2.5 minutes as opposed to every 10, according to Ars Technica. Instead of focusing on hefty transactions, Litecoin targets merchants who need a large volume of small transactions to be processed relatively quickly. As of Monday, it was trading at a rate of $101 with a market cap of around $5.47 billion.