Ark Invest's Cathie Wood is a big believer in Bitcoin (BTC -0.66%). She launched Ark's first spot price Bitcoin exchange-traded fund (ETF) in January once regulators gave their approval.

Earlier this year, Wood raised her price target from $1 million to $1.5 million by 2027 -- which would represent a whopping 2,139% jump from Bitcoin's recent price of about $67,000. Wood expects that explosive growth to be driven by three tailwinds: the approvals of Bitcoin ETFs, institutional purchases of those ETFs, and the expected halving next month, which will cut the rewards for mining Bitcoin in half.

A digital illustration of Bitcoin tokens on a circuit board.

Image source: Getty Images.

We should take those estimates with a grain of salt, since Wood has a habit of making wildly bullish predictions and not necessarily delivering; her flagship Ark Innovation ETF, for example, has only risen 13% over the past five years as the S&P 500 rallied 88%. That said, we should still consider whether Wood's bullish thesis makes sense and if Bitcoin is worth buying.

The bull case for Bitcoin

The bulls believe Bitcoin will eventually join gold, silver, and other precious metals as a hedge against long-term inflation. Like the gold bugs, Bitcoin's bulls believe that fiat currencies are destined to depreciate, and the trend will drive more governments, businesses, and investors to adopt the cryptocurrency. Up until this January, most of those people invested in Bitcoin in three ways: through direct purchases on a crypto exchange like Coinbase, through a trust like Grayscale Bitcoin Trust, and through ETFs that were pinned to Bitcoin futures.

But all three methods had drawbacks. Crypto exchanges were disconnected from the public stock exchanges, prone to sudden disruptions and outages, and frequently targeted by regulators. The collapse of FTX and the recent criminal charges against Binance also rattled investors' confidence in stand-alone cryptocurrency exchanges.

Crypto trusts were more secure and could be actively traded on the stock market, but they charged high fees. Bitcoin future ETFs also charged high fees, but they often failed to keep pace with the cryptocurrency's actual spot prices. The Securities and Exchange Commission's approvals in January of the first 11 spot price Bitcoin ETFs resolved those issues; the ETFs charge low fees, are directly tied to Bitcoin's spot price, and can be easily traded on the open market.

Wood believes those new ETFs will drive institutional investors to buy more Bitcoin. Back in December 2021, Wood predicted that if institutional investors allocated an average of 5% of their portfolios to Bitcoin, it would boost its near-term price by about $500,000. Wood reiterated that bullish view earlier this month and said that institutional buyers would drive Bitcoin's price to $1.5 million as it's recognized as a new asset class.

Meanwhile, Bitcoin will undergo its next halving in April. That process, which occurs every four years, cuts in half the reward for miners like Marathon Digital to mint new Bitcoin -- but it might help boost Bitcoin's price as market demand outstrips its slowing supply growth.

At the same time, persistent inflation and escalating geopolitical conflicts could drive more countries to adopt Bitcoin as a mainstream currency. That trend could accelerate Bitcoin's transformation into a reliable, safe asset like gold and silver.

But is Bitcoin really headed to $1.5 million?

Cathie Wood isn't alone in her bullish view for Bitcoin's future. The British bank Standard Chartered says its price will hit $100,000 by the end of 2024, while the financial services giant Fidelity predicts its price will reach $100 million by 2035 and $1 billion by 2038. It's impossible to say if those predictions will come true, but the approvals of the first spot Bitcoin ETFs could set a floor under its volatile price.

So instead of wondering if Bitcoin will deliver a 2,000% gain in just three years, investors should simply ask themselves if they believe the bullish argument. If Bitcoin sounds like a promising investment, then it might be smart to accumulate some Bitcoin or shares of a low-fee spot price ETF as a long-term growth play.