Blockchain technology has received tremendous attention during the last decade. Huge investments incentives have been made into Blockchain technology and companies worldwide are adapting the new modern innovation. Advocates for Blockchain technology claims that the safe and transparent distributed decentralized ledger has the potential to transform entire industries. One of the biggest operational risks for financial institutions is risks associated with cyber security and cybercrimes. It is argued that Blockchain technology should reduce possibilities for cyber-attacks, increase transparency, and reduce risk. No previous research has been found to confirm this research proposition with perspective to stock return. Still, there remain uncertainties regarding how Blockchain technology affects individual businesses, operational activities and stock behaviours. This research gap is aimed to be partly bridged with this thesis in a Swedish setting.  The primary purpose with this study is therefore to study if the introduction of Blockchain technology in Swedish corporations have an impact of stock return volatility. The longitudinal research methodology of this thesis is designed to satisfy a deductive, quantitative research design, with objectivist ontological assumptions and epistemological positivist approach to generate axiological value-free results. Multiple Linear Regressions and Panel data regression have been performed as well as t-tests to test two hypotheses with regard to systematic risk and total risk as measurements for historical volatility of returns.   The primary findings show a non-significant slight reduction for total risk of stock return, and a slight increase in the systematic risk of stock return. Using mathematical set theory one can argue that the unsystematic risk of stock return decreases. This has proven to be in line with previous theoretical research suggestions which states that operational risk should be reduced. However, the effects observed through the statistical procedures are quite small. Thus, this could indicate that investors’ perceptions of Blockchain technology are still associated with negative issues.  Financial theories such as asymmetry of information, adverse selection, signalling, risk-return fundamentals and behavioural aspects of finance are applied to describe the results, together with previous research, to use the theoretical framework in a coherent way. More research is emphasized to further explore this phenomenon, in order to draw generalizable, significant conclusions though different geographical contexts and markets.  <img src="blob:https://umu.diva-portal.org/2dd6dec1-d82a-4a8e-8093-18a24087fcb2" />