For Wall Street—type investors seeking to buy and hold bitcoin or risk-happy prospectors looking to make a quick buck, such price swings are generally a feature, not a bug. It ran on a computer controlled by Ulbricht. The dollar and euro are stable, with prices shifting just a few percent per year. Contraband sales, like other illegal applications of cryptocurrency including ransomware, have largely switched to newer digital currencies like Monero and Zcash , both of which promise far greater privacy by default. The researchers point out that they used only easily spotted addresses and simple matching techniques. Though bitcoin initially promised completely anonymous transactions, the public nature of the blockchain system in fact has always meant that savvy observers could amass huge amounts of information on bitcoin users, identifying the addresses of popular darknet markets and making money-laundering more onerous.