Cryptocurrency developers build these protocols on advanced mathematics and computer engineering principles that render them virtually impossible to break, and thus to duplicate or counterfeit the protected currencies.
Using data from a prominent blockchain research firm, Coinmetrics.io, we explore the relationship between prices, computing power (measured by the hashrate), and network (measured by the number of unique active users). We focus on five major mineable cryptocurrencies (i.e. Bitcoin, Ethereum, Monero, Litecoin, and Dash). In some of our test, we expand our data to include an additional 33 cryptocurrencies. Our sample period spans from 7 August 2015 to 25 January 2019.

HONG KONG/BEIJING (Reuters) -Didi Global is preparing to relaunch its ride-hailing and other apps in China by the end of the year in anticipation that Beijing's cybersecurity investigation into the company will be wrapped up by then, three people directly involved in the relaunch said. The people, who declined to be identified as the information was private, said they expected China's cyberspace regulator to finalise any penalties on the company in December. In July, the powerful Cyberspace Administration of China (CAC) ordered app stores to remove 25 mobile apps operated by Didi - just days after the ride-hailing giant listed in New York.
The SADF test finds the largest ADF statistic from all the windows considered. If this value exceeds a critical value, the null hypothesis can be rejected, and it is deemed the series displays explosive behaviour in at least one of the windows (taken as indication of a bubble occurring).