Last year has become an important milestone for bitcoin. Even those who do not know what digital currency means, must have heard the magic word, bitcoin, at least once or twice. The word bitcoin is everywhere: in newspapers, on TV, on radio, on the Internet. This is not surprising, where more than eleven months in 2017, this digital currency has grown 20 times (from USD 900 per 1 coin to almost USD 20,000). The surge in demand is pushing it higher and higher even as the queue of those who want to earn unexpected profits are collected on crypto exchanges. And then, suddenly, in just one week that runs from December 12 to December 17, bitcoin loses more than 45% of its value. This devastating collapse shows that a strategy based on a "buy only" approach is not always beneficial for traders and investors, it can also be a disaster.