In the basement of Brian Samson's house in Middletown, Delaware, computer hardware hums softly beneath monitors with scrolling lists of seemingly random numbers and letters. As Samson goes about his day as a web designer and app developer, the setup earns him money in the form of digital currency. The best-known type, bitcoin, is how 36-year-old Samson began investing in the growing world of so-called cryptocurrencies four years ago. Intrigued by the technology used, which eliminates the need for traditional banks in transactions, he became both an investor and one of the "miners" who keep the system going.

"It gives control to people instead of a government, and I like that," Samson said. "And its value is going up. I like that, too."

In simple terms, bitcoin — which dates only to 2009 — is part currency, part commodity. It can be used as payment for transactions at companies that accept it the same way U.S. dollars are, or it can be viewed as an investment similar to gold. As of Tuesday morning, one bitcoin was equal to about $4,066. So far this year, it's up more than a whopping 333 percent. The total value of all bitcoins in existence (roughly 16.5 million) stands at about $66 billion. Add in the other few hundred cryptocurrencies and it's a $141 billion market.

A large monitor keeps cryptocurrency miner and investor Brian Samson updated on his earnings. Salvatore Agostino

Yet these new assets comprise just a fraction of the world's multi-trillion currency market. And as a new asset with a smaller pool of investors, cryptocurrencies are subject to wild swings in value. In the last week alone, for instance, one bitcoin has ranged from a high of $4,463 to a low of $3,283. It's also largely unpredictable which digital currencies will have staying power. Like any new market — remember all those dot.com busts? — it can take years for a shakeout and for lawmakers and regulators to figure out their oversight approach. Already, the anonymity that comes with these digital transactions raises concerns of money laundering and the funding of illicit activities. Another major difference is that bitcoin's creation, value and integrity come from complicated, mathematical wizardry, known as "blockchain" technology, that regulates the creation of new units and ensures the security of every transaction involving the digital currency. That's where Samson comes in as a miner. Basically, new bitcoins come into circulation via these miners. (See chart below.) When 21 million units are reached, expected in 2040 or so, no more bitcoins will be created.

Source: Blockgeeks.com Certified Financial Planner Samuel Boyd calls himself a fan of bitcoin, due to the blockchain technology underlying it. Nevertheless, he cautions that it's part of a young asset class that comes with many unknowns. "From an allocation standpoint, think of it as an alternative investment," said Boyd, senior vice president of Capital Asset Management Group in Washington, D.C. "You wouldn't want more than 5 percent of your overall allocation in it." While still a sliver of the investment universe, bitcoin is slowly gaining a little respect from traditional financial institutions. For instance, Boston-based Fidelity Investments recently began allowing clients who hold digital currencies on Coinbase, an online platform for storing and exchanging assets, to view them on the Fidelity website.

Shoshi Bacon says investing in Bitcoin has been "a fascinating and exciting ride." David Heller

Yet from the perspective of Samson and other bitcoin investors, digital currency is changing the way the global financial system works whether corporations realize it or not. Samson, who paid $80 for his first bitcoin in 2013, said he's earned about $140,000 in the digital currency from his mining activity and investing. He said he also holds roughly $26,000 in Litecoin and Ethereum from mining income. Shoshi Bacon, of Forest Hills, New York, began investing about a year ago when one bitcoin was worth $500. Since then, she has put a "significant chunk" of her net worth in bitcoin. "It's been a fascinating and exciting ride," said Bacon, who is in her 50s. "The potential for the future of blockchain [technology] is just amazing. It's a whole new frontier of opportunity."

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