Meanwhile, there has been plenty of speculation that bitcoin’s big rise may have been due to a pump-and-dump scheme. One theory that the U.S. Justice Department is reportedly looking into is that the digital coin Tether (which is supposedly pegged to the U.S. dollar to make for a less volatile cryptocurrency) was used to manipulate the bitcoin market and cause a large run-up in price. This theory stems from an academic paper, which cast Tether in a very damning light. And it also led many to believe that the initial bitcoin craze was manufactured and destined to bust.
Meanwhile, even the most enthusiastic bitcoin evangelists are realizing that a retooling is in order. Michael J. Casey, a senior adviser for blockchain research at MIT’s Digital Currency Initiative, recently wrote about how the crypto-winter has arrived, but it may lead to better things down the line:

Additionally, because there is no physical product or centralized organizing body, it is hard to point to anything and say “see, that good thing happened, crypto values will increase now”. So how does cryptocurrency gain value?
Like all cryptocurrencies, the majors are digital assets that secure and verify transactions using computer science and complex mathematics, known as cryptography. Unlike traditional (‘fiat’) currencies, they are not currently issued or backed by a central authority such as a government. Instead, they run across a network of computers and are underpinned by blockchain technology – a permanent record of transactions that cannot be altered without the consensus of the network.