*Communication* **Contagion E** ff**ect in Cryptocurrency Market**

**Paulo Ferreira 1,2,3,\* and Éder Pereira 4,5**


Received: 11 June 2019; Accepted: 8 July 2019; Published: 10 July 2019

**Abstract:** The rapid development of cryptocurrencies has drawn attention to this particular market, with investors trying to understand its behaviour and researchers trying to explain it. The evolution of cryptocurrencies' prices showed a kind of bubble and a crash at the end of 2017. Based on this event, and on the fact that Bitcoin is the most recognized cryptocurrency, we propose to evaluate the contagion effect between Bitcoin and other major cryptocurrencies. Using the Detrended Cross-Correlation Analysis correlation coe fficient ( <sup>Δ</sup>ρDCCA) and comparing the period after and before the crash, we found evidence of a contagion e ffect, with this particular market being more integrated now than in the past—something that should be taken into account by current and potential investors.

**Keywords:** cryptocurrency; contagion e ffect; detrended cross-correlation analysis; Bitcoin
