In brief: The world's leading cryptocurrency by market cap smashed another milestone on Thursday as the value of a single Bitcoin eclipsed the $40,000 mark for the first time. If this all sounds a bit familiar, well, it should.

Less than one week ago, Bitcoin achieved another major milestone for the first time, pushing past $20,000 per for the very first time. That record was almost set back in 2017 but the cryptocurrency fell just short before losing much of its value over the following year.

At present, Bitcoin's market value means it is nearly worth as much as Tesla, the seventh most valuable company in the US. The total market cap of all cryptocurrencies combined topped $1 trillion on Thursday.

At $40,000 per, there are no doubt a lot of newly minted millionaires out there today and several more that are simply adding to their wealth.

Square CEO Jack Dorsey back in October, for example, took $50 million of the company's money and bought Bitcoin with it (when they were trading for around $11,000 each). At today's valuation, that investment is worth nearly $182 million.

Likely contributing to the recent crypto rally is PayPal's recent move into the market. In November, the financial services company started allowing users in the US to buy, hold and sell four types of popular cryptocurrency including Bitcoin. Since that announcement, PayPal's share value is up 23 percent.

Masthead credit Tom Stepanov