In December of last year, bitcoin nearly touched $20,000 per coin for the first time in its history; but it currently stands at just under $7,000, as of March 31, 2018. Despite this whipsawing – and caution from some prominent figures in the financial world that bitcoin and cryptocurrencies more broadly could be a bubble – investors are still piling on. However, while those who bought into bitcoin early on and while the price of each coin was low are enjoying massive gains at this point, not every investor is as interested in buying when the coin has reached record high levels. Fortunately for those investors, there are many other digital currencies available today, and in fact there are new currencies emerging all the time. Many of these currencies will not succeed, but there is a chance that some could go on to be the next big star of the digital currency world. Here are a few obscure cryptocurrencies worth keeping an eye on for the rest of 2018.

Vertcoin

Many currencies in existence today owe their origins – as well as their underlying structures and networks – to bitcoin. Vertcoin is one of these cases. It was built to incorporate additional decentralization measures, and the development team has a consistent track record of improving the underlying network. According to Coin Market Cap, there are currently over 41 million VTC in circulation, with a maximum supply of 84 million. It currently trades for $1.64 per coin, as of March 31, 2018, but is highly volatile, trading at over $9 per coin in January of this year.

IOTA

IOTA is a digital currency which focuses on secure payments between machines in the Internet of Things. It is unique among cryptocurrencies in that it does not feature an underlying blockchain support network. Instead, it makes use of directed acyclic graph technology. Through this technological undergirding, IOTA transactions are always free, regardless of the size of the transaction itself. This technology also allows for scalability and faster processing times, as well as a theoretically unlimited number of transactions. All of these have been issues which have plagued industry leader bitcoin. If IOTA is able to capitalize on this technology, it could eventually come to dominate the industry. The current price is $1.09.

Cardano

Another fully open-source project, Cardano is a cryptocurrency looking to revolutionize smart contracts. According to the developer website, Cardano "seeks to deliver more advanced features than any protocol previously developed." As of March 31, 2018, Cardano tokens sell for under $0.15 each, and the total market cap of the currency is $4.83 billion. There are nearly 26 billion tokens in circulation out of a maximum of 45 billion, according to Coin Market Cap.

Will any of these cryptocurrencies overtake bitcoin to lead the field? It's impossible to say, but investors interested in the space may wish to keep an eye on them in any event.