Bitcoin's (BTC-US) bulls and bears have been more active than ever this year as the cryptocurrency hovers around $46,000. Notable heavy hitters have publicly talked up — or down — the coin as it soared to new highs earlier this year.

Tesla (TSLA) and SpaceX founder Elon Musk is arguably the most notable crypto bull, and his tweets can move the coin's price. Bitcoin spiked earlier this year when Tesla initially announced it had bought bitcoin and would soon be accepting it as payment.

"Elon's comments and actions do have an impact on crypto, specifically Bitcoin, specifically Dogecoin (DOGE-USD)," YouTube host Matt Kohrs tells Yahoo Finance.

"Him as a person, I would say it has direct impacts. Other individuals though, I don't really think the effect is as large or really if any," he noted.

Other bitcoin bulls include the founder of Ark Invest, Cathie Wood. Her team is creating a bitcoin-focused ETF. Wood's analysts have a $500,000 price target on the coin.

MicroStrategy's (MSTR) founder and CEO Michael Saylor boldly added the cryptocurrency time and again on his company's balance sheet.

Twitter's (TWTR) CEO Jack Dorsey, a crypto advocate for years, recently said bitcoin will be a big part of the company's future. Twitter is one of big names which have announced strategies involving crypto.

"When you have these big swingers coming out, such as Apple (AAPL) or MasterCard (MA), I mean, that's a big deal. Cause like it gives it credence that it is a legitimate store of value. Something that could be traded as a currency. So I think that's very, very important," said Kohrs, noting the coin is taking on a new "social acceptance."

'The long term future is tenuous'

But the cryptocurrency also has notable bears, including legendary investors Warren Buffett and Charlie Munger. Buffett once called bitcoin "probably rat poison-squared."

At Berkshire Hathaway's (BRK-A) (BRK-B) annual shareholder meeting in May, Munger said, "Of course, I hate the bitcoin success, and I don’t welcome a currency that’s useful to kidnappers and extortionists, and so forth ... So, I think I should say modestly that I think the whole damn development is disgusting and contrary to the interests of civilization. And I'll leave the criticism to others." At their 2018 shareholder meeting, Munger called the coin a "turd."

Economist and Stern School of Business professor Nouriel Roubini is another bear. He has told Yahoo Finance, "It's not scaleable, it's not secure, it's not decentralized, it's not a currency."