The trillion-dollar market value has a new member: bitcoin. The total number of bitcoins trading are now collectively worth more than US$1 trillion.

That's because the price of a bitcoin hit a number of new all-time highs Friday. One bitcoin currently costs nearly $53,400 -- and there are about 18.6 million bitcoins in circulation according to Coinbase. (The total number of bitcoin eventually available is capped at 21 million.)

Of course, it's not an apples-to-apples comparison to look at bitcoin versus big firms with sky-high valuations like Apple. But for what it's worth, only four companies in the United States currently are worth more than bitcoin: Apple, Microsoft, Amazon and Google owner Alphabet.

Bitcoin currently is worth about $225 billion more than Tesla, the company that is most responsible for the most recent surge in the cryptocurrency's price.

The Elon Musk-led electric car juggernaut announced earlier this month that it now owns $1.5 billion's worth of bitcoin in its corporate coffers. Tesla also said it was looking at letting consumers use bitcoin to buy its cars and SUVs.

That news has sparked speculation that other big companies may soon add bitcoin or other cryptocurrncies to their balance sheets, since bitcoin is generating a significantly higher return than bonds and cash.

Corporate America is validating bitcoin. Payments giants Square and PayPal let their users buy and sell it. Credit card processing behemoths Visa and Mastercard are also embracing cryprocurrencies.

And a top strategist at BlackRock, the world's largest asset manager, said on CNBC this week that the company has "started to dabble" in bitcoin as an investment.

All this has helped spark a wave of buying by average investors. Consumer research firm Piplsay wrote in a report Thursday that half of the more than 30,000 consumers it surveyed this week about bitcoin said they felt it was "safe" to invest in cryptocurrencies.

Bitcoin prices have surged more than 80% so far this year, and investors are enthusiastically scooping up other cryptocurrencies as well. Ethereum, the world's second largest cryptocurrency with a total value of about $220 billion, has more than doubled this year.

And the price of dogecoin, a currency that originally started as a dog meme-based joke, also has skyrocketed this year following several bullish tweets about it by Musk and support from traders on Reddit.