Digital currency fans are partying like it’s 1999.

Late last month, more than 300 people crowded onto a rooftop bar in Manhattan to celebrate Ethereum, the latest cryptocurrency to soar and capture speculators’ imaginations.

The gathering, under a sunny late-afternoon sky, was about six times bigger than organizers expected, a miniature version of dot-com days when explosive new technology pulled in people with visions of changing the world and getting rich.

“If somebody gives you a chance to jump on a rocket ship that’s taking off, you don’t say no,” said Tricia Lin, a 35-year-old from New Jersey who recently quit her job at Morgan Stanley to pursue a future in digital currencies. Bouncing around from one idealistic conversation to another, she added: “It’s so different from the finance industry.”

It has been a galvanizing year for Ethereum and the more established bitcoin, both of which have shattered records in 2017. A new method of fundraising, initial coin offerings, has pulled in more than $1 billion collectively for startups in the first six months of 2017, boosting Ethereum in particular since it is the main currency used to fund the deals.