Ifigeneia Georgoula, Demitrios E. Pournarakis, Christos Bilanakos, Dionisios N. Sotiropoulos · 5 authors
This paper uses time-series analysis to study the relationship between Bitcoin prices and fundamental economic variables, technological factors and measurements of collective mood derived from Twitter feeds. Sentiment analysis has been performed on a daily basis through the utilization of a state-of-the-art machine learning algorithm, namely Support Vector Machines (SVMs). A series of short-run regressions shows that the Twitter sentiment ratio is positively correlated with Bitcoin prices. The short-run analysis also reveals that the number of Wikipedia search queries (showing the degree of public interest in Bitcoins) and the hash rate (measuring the mining difficulty) have a positive effect on the price of Bitcoins. On the contrary, the value of Bitcoins is negatively affected by the exchange rate between the USD and the euro (which represents the general level of prices). A vector error-correction model is used to investigate the existence of long-term relationships between cointegrated variables. This kind of long-run analysis reveals that the Bitcoin price is positively associated with the number of Bitcoins in circulation (representing the total stock of money supply) and negatively associated with the Standard and Poor's 500 stock market index (which indicates the general state of the global economy).
Bitcoin has two major roles: as currency and as financial asset. This paper attempts to address these roles: whether Bitcoin is a real currency, and what its financial features are. Using daily data of the exchange rates quoted from the world major Bitcoin dealer since the inception of Bitcoin and the spot market exchange rates, we calculate the triangle arbitrage asset price to decompose the features of this currency. The results suggest significant liquidity discount of Bitcoin and risk premium as a financial asset in terms of British Pound Sterling (2.46%) and Chinese Yuan (0.3%). There is idiosyncratic risk component associated with Bitcoin implied by the Granger causality tests. Bitcoin, as investment objectives instead of currency unit, is associated with excess risk and low returns. Such poor performance discourages investors to spend Bitcoin as currency and to pursue the arbitrage profit. Investors store and hold Bitcoin as fixed asset. In addition, both arbitrage stickiness and low Treynor ratio are persistent over time.
The present paper seeks to effectively address the following question: What Bitcoin looks like? To do so, we regress Bitcoin price on a number of variables (Bitcoin fundamentals recorded in the literature) by applying an ARDL Bounds Testing approach for daily data covering the period from December 2010 to June 2014. Our findings highlight the speculative nature of Bitcoin. We also provide insightful evidence that Bitcoin may be used for economic reasons but there is any sign of being a safe haven. By considering the Chinese trading bankruptcy and the closing of Road Silk by FBI, the contribution of users’ interest stills sharply dominant, indicating the robustness of our results.
The Bitcoin has emerged as a fascinating phenomenon in the Financial markets. Without any central authority issuing the currency, the Bitcoin has been associated with controversy ever since its popularity, accompanied by increased public interest, reached high levels. Here, we contribute to the discussion by examining the potential drivers of Bitcoin prices, ranging from fundamental sources to speculative and technical ones, and we further study the potential influence of the Chinese market. The evolution of relationships is examined in both time and frequency domains utilizing the continuous wavelets framework, so that we not only comment on the development of the interconnections in time but also distinguish between short-term and long-term connections. We find that the Bitcoin forms a unique asset possessing properties of both a standard financial asset and a speculative one.
Alloreactivity after transplantation is associated with profound immune suppression, and consequent opportunistic infection results in high morbidity and mortality. This immune suppression is most profound during GVHD after bone marrow transplantation where an inflammatory cytokine storm dominates. Contrary to current dogma, which avers that this is a T-cell defect, we demonstrate that the impairment lies within conventional dendritic cells (cDCs). Significantly, exogenous antigens can only be presented by the CD8(-) cDC subset after bone marrow transplantation, and inflammation during GVHD specifically renders the MHC class II presentation pathway in this population incompetent. In contrast, both classic and cross-presentation within MHC class I remain largely intact. Importantly, this defect in antigen processing can be partially reversed by TNF inhibition or the adoptive transfer of donor cDCs generated in the absence of inflammation.
The present paper seeks to effectively address the following question: What Bitcoin looks like? To do so, we regress Bitcoin price on different variables (potential Bitcoin fundamentals recorded in the literature) by applying an ARDL Bounds Testing approach for daily data covering the period from December 2010 to June 2014. Our findings highlight the speculative behavior of Bitcoin. This virtual currency may be also used for economic reasons. However, there is any sign of being a safe haven. By considering the Chinese trading bankruptcy, the contribution of speculation (proxied by investors’ attractiveness to Bitcoin) remains dominant, indicating the robustness of our results.
The present study addresses one of the most problematic phenomena: Bitcoin price. We explore the Granger causality for two relationships (Bitcoin price and transactions; Bitcoin price and investors’ attractiveness) from a frequency domain perspective using Breitung and Candelon’s (2006) approach. Intuitively, this research gauges empirically the causal links between these variables unconditionally on the one hand and conditionally to the Chinese stock market and the processing power of Bitcoin network on the other hand. The observed outcomes reveal some differences with respect to the frequencies involved, highlighting the complexity of assessing what Bitcoin looks like and the difficulty to gain clearer insights into this nascent crypto-currency. Beyond the nuances of short-, medium- and long-run frequencies, this paper confirms the extremely speculative nature of Bitcoin without neglecting its usefulness in economic reasons (trade transactions). The consideration of the Chinese market index and the hash rate has led to solid and unambiguous findings connecting further Bitcoin to speculation.
This paper discusses the potential and limitations of Bitcoin as a digital currency. Bitcoin as a digital asset has been extensively discussed from the viewpoints of engineering and security design. But there are few economic analyses of Bitcoin as a currency. Bitcoin was designed as a payments vehicle and as a store of value (or speculation). It has no use bar as money or currency. Despite recent enthusiasm for Bitcoin, it seems very unlikely that currencies provided by central banks are at risk of being replaced, primarily because of the market price instability of Bitcoin (i.e. the exchange rate against the major currencies). We diagnose the instability of market price of Bitcoin as being a symptom of the lack of flexibility in the Bitcoin supply schedule ‐ a predetermined algorithm in which the proof of work is the major driving force. This paper explores the problem of instability from the viewpoint of economics and suggests a new monetary policy rule (i.e. monetary policy without a central bank) for stabilizing the values of Bitcoin and other cryptocurrencies.
Bitcoins are digital gold. They are a purely electronic commodity traded for speculative purposes as well as in exchange for goods and services. Just like physical gold, the relative price of bitcoins denominated in different currencies implies a nominal exchange rate. This is a departure from previous literature which treats bitcoin prices themselves as nominal exchange rates. I argue that treating prices as exchange rates is inappropriate as one would not consider the price of physical gold to be an exchange rate. Therefore, this paper characterizes the behavior of nominal exchange rates implied by relative bitcoin prices. I show that the implied nominal exchange rate is highly cointegrated with the nominal exchange rate determined in conventional foreign currency exchange markets. I also show that the direction of causality flows from the conventional markets to the bitcoin market and not vice-versa which can explain much of the volatility in bitcoin prices.
The complexity and interdependence of the economies of various geographical and political entities have one generic binder - money. The economic history of the last century, replicated in the first decade of our century, can be “written” with money. Indeed, money, a multiple discovery of the civilization in its historical way, was and still is the guardian of hope for prosperity. The disputes about money clearly indicate the need, opportunity and the possibility of monetary competition, which would provide, from the point of view of entrepreneurs, the most suitable production of money based on expectations of their economic preferences. Increasingly more, theorists, practitioners and analysts bring to the fore the issue of simultaneously using the official currency and the digital one. Thus, the issue of the public debate regarding the private money is still of interest. Based on these considerations, this paper aims to highlight how the digital currency Bitcoin can meet the challenges of the economic environment, taking into account both the opportunities and the threats to which it is subject, and the records emphasized by the history of economic thought and adapted to the current reality.
An important function of the financial system is to serve as a key source of information that helps coordinate decentralized decision-making in various sectors of the economy. Households and investors use interest rates, futures prices and security prices in making their consumption-saving decisions and portfolio allocation decisions. Interest rates and prices provide important signals to managers of firms in their selection of investment projects and financings. This paper illustrates the role played by financial markets in providing information about the future volatility-that is, the degree of uncertainty-of economic variables such as interest rates, exchange rates, commodity prices, and stock, bond and other security prices. It has two basic goals: (1) to show the importance of volatility for all sorts of policy decisions in the private and public sectors of the economy; and (2) to show how ex ante estimates of future volatility can be extracted from the prices of securities.
Security breaches of the cryptocurrency exchanges usually cause the price fluctuation in the market. Approximately one hundred cryptocurrency thefts, including hacks and scams, has occurred since 2012 to 2018, half of which are hacks of Bitcoins. Based on the thirty Bitcoin hacks, this study portrays the general price pattern during the hack. And it illustrates the link between the size of the hack and the subsequent price change of Bitcoin. The tests reveal that the larger the volume of the hack, the stronger the price drop. However, a similar obvious relationship does not exist for the recovery of the price. The study might be the first piece of research focus on the hacks and the price pattern in a short time period.