Our study employs a systematic review process. Consequently, to ensure the integrity of our sample, we follow Liang et al. (2016), Linnenluecke et al. (2020), Jiang et al. (2021), and Yue et al. (2021), and focus our search in Web of Science database (WoS).

As Satoshi Nakamoto, in late 2008, was the first to contribute to cryptocurrency literature, we use that initial landmark as a reference date for our study and searched the WoS database from the 1/1/2009 to 04/11/2021.

In our systematic review process we adopted and adapted the systematic review protocol from Briner and Denyer (2012, p. 121) presented in Table 1.

In contrast to other authors such as Flori (2019a), Kyriazis et al. (2020), Haq et al. (2021), Jalal et al. (2021), our approach considers a broader keyword scope since we do not consider restrictive words regarding investor behavior and behavioral finance in the cryptocurrency market. Therefore, the selected keywords in our review are: “Cryptocurrency”, “Cryptocurrencies”, “Bitcoin”, “Portfolio diversification”, “Investment”, “Investor”, “investors”, and “Alternative investment”. However, when we applied the Boolean operators and wildcard characters to the selected keywords, the following research equation emerged: “cryptocurrenc* OR Bitcoin AND diversification AND portfolio AND invest* AND alternative” as evidenced in Table 1. The search equation focused on the “topic” option that searches within the title, abstract, author keywords and keyword plus. Additionally, we applied our quality criteria. We included only English-written academic journals that addressed the topic of cryptocurrencies from the investor or investment perspective from the Academic Journal Guide ABS (Association of Business Schools) list of 2021.