This paper aims to study the regulatory impacts of the rise and development of fintechs, which can be defined as technology financial companies that have shaken the financial market with disruptive innovations and completely altered the dynamics and functioning of the sector due to the application of computational technologies such as big data analytics, algorithms, artificial intelligence and machine learning. With a special focus on prudential and systemic regulation, the research identifies the problem of systemically relevant regulatory disconnection and seeks to offer a solution within the theoretical framework of dynamic regulation, through an experimental tool: the regulatory sandboxes. Starting from the premise that the speed of the digital technological transformations caused by the fintech phenomenon is capable of generating regulatory difficulties within the normative function exercised by Regulatory Bodies, giving rise to the problem of regulatory disconnection, that is, the rupture between the normative framework and the new reality of the sector, this work is intended to tackle two questions. First, it is investigated whether systemic risks, arising from the new dynamics of fintechs, are neglected, as a result of regulatory disconnection on the financial market, and therefore raising the problem of systemically relevant regulatory disconnection. Secondly, it is sought to investigate whether, in light of its peculiar characteristics, regulatory sandboxes prove to be a useful tool to solve or mitigate such a problem. The hypothesis is that, due to the dawn of the technological-financial innovations deriving from the fintech phenomenon, new sources of systemic risk arise, as a consequence of the application of new computational technologies and the profile of new entrants in the market. This fact then could have the potential of creating an environment able to worsen the systemic regulatory disconnection, especially in light of the current prudential and systemic regulatory rules that, due to the global financial crisis, are mainly concerned with supervising the performance of large financial conglomerates, causing new risks not included in this category to come to be unwillingly neglected. In addition, it is suggested that regulatory sandboxes, as an incentive tool based on structured experimentalism, are able to mitigate the problem of systemically relevant regulatory disconnection by allowing the testing of innovative products and services in a controlled environment under the supervision of the regulator, making it possible to reduce the informational asymmetry between regulator and the market, thus enabling the updating of the normative-regulatory framework in a timely or less outdated manner. In addition, such a mechanism allows the regulator to address the double challenge imposed by the new dynamics of fintechs of fostering innovation and competitiveness in the financial market, while ensuring the financial stability and systemic solidity of the sector.