The price of one bitcoin (XBT) topped more than $40,000 Thursday, January 7 -- double the value from a little more than three years ago. Prices later slid back to around $38,000.
Bitcoin first topped $19,000 in December 2017 before crashing spectacularly to around $3,200 a year later.
The value of all bitcoins in circulation is now more than $740 billion and the total value for all cryptocurrencies is more than $1 trillion, according to CoinMarketCap.
Investors have flocked to bitcoin in recent months as the cryptocurrency has gone mainstream.
Square (SQ) and PayPal (PYPL)now let their users buy and sell bitcoin. Top money managers including Paul Tudor Jones, Stanley Druckenmiller -- and more recently, Anthony Scaramucci -- have embraced it.
Software firm MicroStrategy (MSTR) is now holding bitcoin on its balance sheet. And a top exec at BlackRock (BLK), the world's largest asset manager, recently said bitcoin is basically a new, digital gold -- an asset that can hold up well during times of dollar weakness and rising inflation.
"It's not surprising to see bitcoin's recent run up. It's encouraging to see more serious consideration of bitcoin and the digital currency asset class broadly, because it has real potential to reshape global finance as we know it," said Michael Sonnenshein, CEO of Grayscale Investments, the world's biggest crypto asset manager, in an email to CNN Business.