There's gold, the precious metal, and then there's digital gold, aka bitcoin.

For about two decades, the relatively easy way to invest in the original gold was to buy an ETF like State Street's GLD.

Starting last month, digital gold – bitcoin (BTC) – now comes in the same convenient package given the approval of bitcoin ETFs.

The biggest gold ETF, the aforementioned GLD, has an expense ratio – a measure of how much an ETF issuer charges investors – of 0.4%. All but one of the 10 newly approved bitcoin ETFs (Grayscale's GBTC is the exception) have a lower expense ratio.

In the blink of an eye, digital gold is cheaper to buy than the OG version.

"*Nobody* expected that to happen this quickly," ETF Store President Nate Geraci posted on X.

Gold – the conventional kind – is viewed as a haven for investors wanting out of the daily – sometimes hourly or less – twists and turns in financial markets. It's not the only option, though gold is generally easier to buy than other non-correlated assets like art, collectibles, real estate, music royalties, etc. A single ounce of gold is worth about $2,000, so a little bit goes a long way toward stashing one's savings. ETFs that hold them take up even less space – just a few bits of data in some brokerage's computers.

Bitcoin is viewed by many as a more modern store of value. And, given that bitcoin ETFs are charging investors relatively little, it's an even cheaper hedge for investors. Ten issuers introduced them on Jan. 11.

Franklin Templeton, for example, charges a 0.19% management fee, the lowest out of all issuers. Most are below 0.30%. By contrast, the biggest gold ETF, the SPDR Gold Trust, charges 0.40%.

Gold is a useful analogy for bitcoin among some investors because of their similarities, but the metal also differs greatly from the cryptocurrency, said Matt Hougan, chief investment officer at Bitwise, one of the bitcoin ETF issuers.

He said gold is better than bitcoin in one way because it has been around much longer, but it’s also worse because bitcoin is much easier to store, move, divide and use – and harder to fake.

“Many people focus on the fact that bitcoin is worse than gold in certain attributes, and that therefore its potential market cap is a fraction of gold's. But what if the more important thing is that bitcoin is better than gold in many ways, and that therefore its addressable market is much larger than gold?” he said. “I actually think that’s more likely.”

Bitcoin's value comes from the fact that it has a limited supply of 21 million bitcoin, which makes it a scarce asset just like gold. It is also self-governed and cannot be influenced by the government, similar to the metal.

“I like to think of bitcoin as digital super gold,” said Austin Alexander, co-founder of LayerTwo Labs, a venture focused on advancing bitcoin. “The digital gold does what gold does but better: It’s more scarce, more durable and more transmissible than gold."