The price of the cryptocurrency Bitcoin has risen more than 12% in the last week, moving past $9,000 early Sunday morning to yet another in a long string of all-time highs. The cryptocurrency’s total market value is now more than $150 billion.
Other cryptocurrencies have also had a very strong week, with Ethereum and Bitcoin Cash also up for the week.
This continues a roughly eight-month winning streak for Bitcoin and other cryptos, which use decentralized ledgers and cryptographic security to move value over the internet. Since April 20, when it was worth just over $1,200 (per Coinmarketcap.com), Bitcoin has risen nearly 650%.
The extended surge can be explained most of all by the entrance of a broader swathe of global retail investors into the market. Previous Bitcoin surges generated headlines and gave skeptics a chance to familiarize themselves with the technology, but it’s far easier for individuals to actually buy cryptocurrency today, through a huge number of online exchanges, than it was back in 2013.
Get Data Sheet, Fortune’s technology newsletter.
All that retail enthusiasm has generated an array of sketchy “initial coin offerings” and even outright scams, signals of a bubble swimming with less-knowledgeable buyers. But the market has also weathered a number of setbacks, including a major crackdown by the Chinese government and a divisive upgrade controversy, without losing steam, suggesting at the least that buyer enthusiasm is durable.
Another fascinating indicator, highlighted last week by Bloomberg, is the adoption of Bitcoin by U.S. survivalists or “doomsday preppers,” who increasingly believe it will (somehow) be more useful after a major disaster than gold or U.S. dollars.
The latest price landmark is also notable because it tees Bitcoin supporters up to adapt one of the internet’s most enduring memes.