This chapter aims to analyze the price efficiency of Bitcoin (BTC), DASH, EOS, Ethereum (ETH), LISK, Litecoin (LTC), Monero, NEO, QUANTUM, RIPPLE, STELLAR, and ZCASH in their weak form between March 1, 2018 and March 1, 2023 and determine whether they experience overreactions. The results show that cryptocurrencies exhibit positive and negative autocorrelations, which can reduce volatility and moderate price fluctuations. The results also show persistence in cryptocurrency returns, suggesting long-term trends or market patterns that individual and institutional investors can exploit. It is essential to recognize that cryptocurrencies are characterized by a high degree of complexity and instability. Investors need to monitor market trends and make the necessary adjustments to their investment strategies to anticipate market changes. Request access from your librarian to read this chapter's full text.

This study investigates whether Bitcoin may act as a safe haven in the capital markets, including France (CAC 40), Germany (DAX 30), the US (DJI), the UK (FTSE 100), Italy (FTSE MIB), Hong Kong (HANG SENG), Spain (IBEX 35), South Korea (KOSPI), Russia (IMOEX), and Japan (NIKKEI 225), as well as in commodities such as gold (GOLD HANDY HARMAN) and petroleum (WTI), and U.S. 10-year sovereign yields, during the 2020-2022 events. The authors analyze the financial integration and movements of markets to understand how BTC behaves during periods of global economic uncertainty. During the stress period, BTC did not integrate with the analyzed markets, suggesting that BTC exhibits properties of a hedge and a safe haven. BTC has properties of a hedge and a safe haven, and investors in these markets can benefit from investing in it as a secure asset and hedge. It is affected by CAC 40, FTSE 100, HANG SENG, and NIKKEI 225 stock indexes, and investors must carefully evaluate their investment strategies and risk tolerance when including BTC in their portfolio. Request access from your librarian to read this chapter's full text.

Objective: The study aims to critically analyse the role of digital currencies in the context of the monetary system and the challenges and implications for monetary liberalism. Method: Critical review based on an analysis of financial doctrine. A descriptive approach was applied to identify the relevant theories, followed by a critical analysis of the perspectives adopted by the authors. The main theoretical arguments are identified and debated. The methodology enables a critical study to be carried out through comparisons. Results and conclusions: The results highlight the clarity of the arguments, the logical solidity, and the relevance of the evidence presented by the authors. The comparative analysis reveals points of convergence and divergence in the arguments. Inclusive interpretation and reflection allowed the implications of the theoretical approaches for the field of study to be analysed. The conclusions reveal the evidence obtained. Implications if the research: They include an in-depth understanding of the financial theories examined at the level of Bitcoin, highlighting contributions and limitations. Promotes the advancement of knowledge in the theoretical field, identifies possible gaps in the literature, and suggests areas for future research. Provides relevant insights for academia, society, and policymakers. Originality/value: It resides in the application of a critical and analytical approach to financial theories, offering a detailed and contextualised review of the literature. The value comes from providing enlightened insights into the theoretical foundations and possible applications, contributing to the advancement of the academic and social fields.

The rising global concern for environmental sustainability has driven a surge in green invest-ments' popularity. This study examines the multifractal characteristics and efficiency of various green stock indexes, such as Clean Science and Technology, ISE Clean Edge Global Wind Energy Index, iShares Global Clean Energy ETF, Nasdaq Clean Edge Green Energy, and Solactive Clean Energy. The research covers the period from October 4, 2021, to October 4, 2023. The central ob-jective of this research is to evaluate the efficiency of clean energy stock markets and dissect their influence on investment decisions and market performance in the realm of green investments. To accomplish this, the study employs the Wright test (2000) and the Detrended Fluctuation Analysis (DFA) method. The findings indicate the presence of negative serial autocorrelation within the Rankings and Signals tests. Furthermore, the DFA analysis concurrently reveals long memory patterns in most green indexes, with the notable exception being the Nasdaq Clean Edge index, which exhibits tendencies toward anti-persistence. These results imply that prices inadequately incorporate available information, resulting in non-i.i.d. price fluctuations. These implications are significant for investors, as they indicate the potential for predictable returns and opportunities for arbitrage and abnormal profits, challenging the assumptions of random walk and information efficiency hypotheses.

The study analyses the influence of the international oil price, focusing on the CBOE Crude Oil Volatility Index and Brent crude oil, on the main exchange rates: EUR/GBP, EUR/USD, GBP/USD, USD/CHF and USD/JPY. The analysis covers the period from 3 January 2022 to 8 December 2024 to examine the relationship between fluctuations in the oil market and the behaviour of exchange rates. The results show that the CBOE index directly impacts the EUR/GBP currency pair, reflecting the influence of global volatility on financial markets. The EUR/USD pair is influenced by the behaviour of the USD/JPY currency pair, showing the interconnection between the major currencies. Brent futures significantly affect the USD/CHF and USD/JPY currency pairs due to the importance of oil as a strategic commodity and the sensitivity of currencies such as the Yen and Swiss franc to fluctuations in energy prices. These relationships show the strong interconnectedness of global markets, highlighting the importance of informed risk management and decision-making strategies in interdependent environments.