These days, we often hear about virtual currencies or cryptocurrencies, such as bitcoin, Ether, Dogecoin and Litecoin. This year, the value of some of these currencies increased substantially, leading some people, including a friend of mine, to start mining them. Apart from their rising value, virtual currencies are attractive because of the way they are produced. Some people see mining virtual currencies as a relatively easy and low-cost option. All you need to do is turn on the mining programme and wait. Some even purchase extra devices to increase efficiency. However, while the activity may be low cost from a human resources perspective, it is time consuming. Many people see mining virtual currencies as just another way to increase passive income but they may end up investing too much, including in mining equipment, or having relatively low expectations. However, they ought to remember that this is a high-risk investment. First, virtual currencies can be hacked. The nature of decentralisation makes your virtual currency both safe and unsafe. Once you lose your virtual currency, you will not get it back because it is not under any organisation’s or institution’s protection. Second, although decentralisation means that virtual currencies cannot be controlled by any organisation, their value can still be affected. For example, in April, bitcoin’s value fell sharply when Turkey banned crypto payments. In conclusion, virtual currencies are just another mode of investment, but are not stable enough to replace normal currencies. But if the risks are fixed, virtual currencies may not be decentralised any more, which may seriously affect their value and appeal. Hence, it is unlikely that they will become commonly used currencies in the foreseeable future. David Yung Ka-ho, Yau Tong