Cryptocurrency sales from successful initial coin offerings, or ICOs, have totaled $13.7 billion in the first five months of 2018, a tally that is nearly double the amount taken in all of last year, according to a recent report from consulting firm Strategy& and Switzerland-based Crypto Valley Association.

ICOs have become a popular way for technology companies to raise money by selling cryptocurrencies to investors directly, rather than rely on venture capital firms or banks to facilitate funding.

The report tallied 537 ICOs so far in 2018, after last year saw 552 ICOs raise a total of $7 billion. Messaging app Telegram accounted for the largest ICO this year, raising $1.7 billion.

Still, it’s not all rosy. Of the 3,470 ICOs announced since the phenomenon emerged in 2013, the report found that only about 33% have closed successfully, while the rest are in limbo. Of the top 20 largest ICOs to close to date, 65% are considered successful or on track, but 20% face major issues.

The U.S., Switzerland and Singapore are still the key hubs for ICOs, but over recent months the U.K. and Hong Kong have gained ground, according to the data. The U.S. remains the top destination, having hosted 56 successful ICOs this year, followed by Singapore with 53. The report also suggested that clearer regulations continue to take shape in cryptocurrency hubs around the world. 

The Middle East did not register a mention in the report, which is not surprising considering many regulators in the region have expressed doubts regarding cryptocurrencies. Still, there is indeed activity in the Middle East’s cryptocurrency space, with the Abu Dhabi Global Market introducing a cryptocurrency regulatory framework in late June.