In addition to the people who use bitcoin as a tool Exchange for transactions, not slight also that invest in platformtersebut. Indeed, since opening and miningpertamanya in 2009 ago, the value of the bitcoin own has increased very exponential. Recorded, since the first released to the point of highest on December 18, 2017 ago, the value of the bitcoin ascended 278.542 fold, from the US $ 0,07 at the beginning of 2010 to $ 19.498 or equivalent to rp259,103,227, -. Not a little too society as well as investors are aware of the risks that may appear when using cryptocurrencytersebut. Fluktuasinya sometimes so massive with changes in dozens percent already a display regular user. A happiness of its own when see Green color in table monitoring bitcoin owned, but Red showing impairment also not rare. With the fluctuations in such a high, cryptocurrency the often receive responses intermingled of the community. The users and investor support and use bitcoin with massive, but institutions regulator continue to try to limit and regulate peredarancryptocurrency the (that and Meredith, 2015). In Indonesia, the bi officially was prohibited the circulatory bitcoin for transactions in Indonesia the grounds 'konvertabilitas and volatility' per January 13, 2018 ago. Obvious question arises, why? See it, this article will discuss simply perspective and arguments of the Central banks to regulate and limit bitcoin. Reasons to be appointed is not the reason is often become public attention as the absence of the possibility of use for illegal transactions, the possibility of the cyber attacks, or the possibility of the fall of the value of massive - 'the Red-Red' on the value bitcoin. This article will take a different perspective, which is about how bitcoin uniquely interact with one of the most basic system rotation of money and banking - liquidity. The rotation of money and banking system in order to understand the interaction, we have to understand the first system rotation of money and banking. Simply put, it can be explained that money printed by the Central Bank - bi to this case - then outstanding in the community through the banks commercial like BCA, independent, and so on. In economics, this concept is called the concept of 'the creation of money'. Money will move from the Central Bank, and spinning through community save money on the banks commercial while Bank commercial lending money back that ditabungkan is to get profits. Bank and the risk in this system, as there are differences period between savings (demand-deposit), which in general can be drawn at any time, with a loan (loan) that has a time payment of the long run, whereas the Bank commercial play the same money. To protect them, the Central Bank menetapkanreserve requirement ratio (rrr) requiring the Bank commercial not to revolve around the deposit money he received, but keep so percent (about 6,5 percent in the case of Indonesia) to be able to serve liquidity. Not just the Red bitcoin in terms of this problem appear for regulator, one of them bi. Citing public bi on Monday (15/1/2018) ago, "risk konvertibilitas that there is no guarantee exchanged Fiat money, let alone the volatility of high prices." The statement in gamblangmenjelaskan concerns the Central Bank akanpertukaran (or konvertibilitas) of the bitcoin dancryptocurrency other into rupiah (called Fiat money or paper money). Why? For the picture is simple, let's note fluctuations of bitcoin at the beginning and end of 2017 ago. On January 1, 2017, one bitcoin equivalent to 997,69 USD, or about USD 13.257.043, -. While on December 31, 2017, one bitcoin the same is worth 13.860,14 USD or equivalent to USD 184,159,667, -. Until the end of the year, the value of bitcoin has jumped more than 1,200. This is where the problem 'konvertibilitas' emphasized by bi look. If a customers buy 1 bitcoin in early 2017, and plan to menguangkancryptocurrency his those in the early 2018, the Bank commercial withdraw money need to be 'bear' increase nilai1,200. it. Imagine the possibility if the same thing happened to, for example, a thousand customer other. Then, in the hypothesis, Bank commercial need to melt around rp184 billion for asset value rp13 billion in just a twelve months. Assuming that have not even take into account the likely investor invest more than one bitcoin, and the possibility of the community among the top go invest investment tens of up to hundreds of bitcoin. Although the picture above only an assumption, the Central Bank that has a mandate to keep the stability rupiah certainly need to take a step preventive. The possibility of the above can be classified as a systemic risk categorized as new. Previously, liquidity problems in banking often connected with the phenomenon of 'Bank run', where the withdrawal of money in the number of many as experienced panic notice conditions worsening economic and others who participate interesting. The problem with the volatility of bitcoin, which up 1,200% in the twelve months, 'dependents' charged to Bank commercial case penguangan bitcoin massively be coupled even with the condition of the Bank run, though the economy in good condition. Then, what if the Bank commercial managed to serve the request? Or, what if people Exchange bitcoin to rupiah choose to not menguangkannya, yet is stored in a savings? Although the case not cause liquidity problems massive, amount outstanding remain increased significantly. This can lead to the Central Bank more difficult to control inflation, especially in the economy do inflation targetting. Scenarios above described the worst possible in the interaction cryptocurrency with real money with explanations that simple. Looking forward in the end, each of innovation finance new must always taken wise. Since the collapse of the economy of the United States in 2008 that one of which caused by not terkontrolnya innovation finance, the world continue to improve. With the crisis, still warm in our memories, phenomenon cryptocurrency the unpredictable certainly be attention and market participants. Of course, the risk of other more often appointed as security concern, the possibility of use for illegal transactions, and the possibility of bubble burst in nilaicryptocurrency like bitcoin remain there is always. Advantage its use, on the other hand, also still a lot. Income high in investing and benefits of transactions are anonymous remained advantage of bitcoin and cryptocurrency other. However, this article to try to explain the simple concern from regulator and the Central Bank behind his policy. With a view from the point of view of a rather different, seramnya bitcoin probably not only 'Red-Red' only.