Bitcoin. Blockchain. Cryptocurrency. ICOs. It's hard to ignore the frenzied, jargon-filled recent headlines around digital currency: China has banned trading it! JPMorgan Chase has warned against buying it! Startups are embracing it every day!

So are tech investors. Bitcoin-related startups raised $343 million from venture capitalists in the first half of 2017, according to CB Insights, and more than $2.2 billion from all sorts of investors so far this year through so-called ICOs, or "initial coin offerings," according to CoinSchedule.

Yet the practical applications of digital currency, and its underlying "blockchain" technology, remain extremely specialized. If you don't work directly in this industry, you're probably not going to start running your business along on the blockchain anytime soon. Meanwhile, good luck charging your customers using only ether or Dogecoins. (Yes, these are real things.)

Bitcoin began as a decentralized, unregulated currency created by and traded between anonymous individuals, one that supposedly couldn't be tracked by government authorities. But as it and other digital "cryptocurrencies" have evolved, along with the public ledger system that makes up the blockchain, much of the bitcoin economy has been increasingly overtaken by big money--or by entrepreneurial prospectors who want to grab a piece of the bubblicious ICO phenomenon.

Outside of its devoted fanbase or the new ICO participants, the actual business of bitcoin is a sideshow for most of us. It is to the economy what the Kardashians are to the entertainment industry: attention-grabbing and influential in certain areas, but more often hype than underlying accomplishment.

So do you really need to care about this stuff?

Practically speaking, probably not. But there are four big exceptions:

1. You have money to burn, and want to invest in something new

Think stocks and bonds--or gold. This is probably the most common use of digital currency for individuals and non-professionals: as an alternative, risky, potentially very rewarding sort of asset class.

"The real application for bitcoin itself is to store wealth for a very long period of time," says Steve Waterhouse, a blockchain-focused investor and former partner at crypto-currency VC firm Pantera Capital. "It's essentially a solution to a problem no one's ever figured out, other than buying gold."

Obligatory disclaimer: This is not investing advice! And if you do want to throw some money after bitcoin, "FOR THE LOVE OF GOD DO NOT INVEST MORE THAN YOU CAN AFFORD TO LOSE," as my former colleague Marc Hochstein, now the managing editor of blockchain-focused publication CoinDesk, recently put it.

Bubble-watchers beware; there are plenty of economists and financial types starting to sound the alarm about investing your (or your company's) money in bitcoin.

"It's worse than tulip bulbs," said Jamie Dimon, the CEO of JPMorgan Chase, during a Barclays conference this month. "It's a fraud, OK?"

His warnings, repeated this week, and the China crackdown sent the prices of bitcoin bouncing up and down over the last couple of weeks. That's not necessarily the best sign for an investment, especially if you want something stable. Yet as of Friday morning it still cost about $3600 to buy a single bitcoin, up from a mere $600 a year ago--meaning that even if the price stabilizes and continues to climb, you may have missed some of the best times to buy.

2. You want to start a digital-currency-related business ... and you don't want to bother with venture capital.

Right now it's crazy easy to fund a startup that's in any way related to digital currency, thanks to ICOs. These "initial coin offerings" are essentially crowdfunding campaigns for anything bitcoin-related: You decide to start a company and sell digital "tokens" in your company to anyone online.

ICOs have quickly become a huge, and controversial, method of startup financing. China banned them this month, the first step in a broader cryptocurrency crackdown, expressing worries that ICOs "disrupts their social order."

Unlike equity crowdfunding or traditional IPOs, ICOs aren't regulated by the SEC. And unlike traditional venture capital, entrepreneurs raising money through ICOs don't have to give up any ownership of their startups to the people who buy their tokens.

That's one reason they're so popular, roping in celebrities ranging from Floyd Mayweather to Paris Hilton. Because there's no regulatory oversight, these offerings have raised funding for some truly ... unique projects. As BloombergView's Matt Levine has been regularly chronicling, recent ICOs include a dental industry "blockchain solution," plus things called TulipToken, BananaCoin and Jesus Coin. Yes, really.

"For entrepreneurs, if they can pull it off and raise money without giving out equity, it's very attractive," says Oivind Lorentzen, an analyst who follows bitcoin and fintech for venture capital firm Oak HC/FT.

But he's quick to add a very important caveat. "There's an incredible amount of fraud in the space."

3. You already work in finance or related technology.

Maybe you have a startup already working in this industry, or maybe you work for a big, established corporation. Enter the blockchain.

This technology has the promise--if not always the execution--of being faster and more reliable than the current systems banks and governments use to move money around the world.

Big companies are intrigued, giving work (and money) to startups that develop blockchain technology, such as Ripple Labs and R3. "A lot of these guys in the banking world say, 'I believe in the blockchain but not the currency,'" Waterhouse says.

No less a skeptic than Jamie Dimon has led his firm to spend money on blockchain-related projects. So have other big banks and tech companies, including Microsoft and IBM.

4. You spend a lot of your professional life thinking about, or avoiding, the law.

The cryptocurrency phenomenon has yielded an entirely new set of financial instruments to regulate, creating lots of potential work for regulators, lawmakers and lawyers.

Of course, cryptocurrency also continues to have plenty of associations with the less legitimate aspects of business. Bitcoin gained prominence in large part thanks to the Silk Road marketplace for illegal drugs and other black-market goods, a legacy that has persisted beyond Silk Road's shutdown. Digital currency also has become increasingly popular among those demanding online ransoms for cyberattacks.