In recent years, the use of big data technologies in the financial sector has become more common. These technologies have the potential to improve the quality of services provided and help financial institutions to reduce their costs and improve performance. Big data is used by practically every major financial institution, including consulting and technology companies providing services in the financial sector. The Bank of Russia survey conducted in summer 2021 demonstrated that this is also the case for the Russian financial market. With the help of such data, financial institutions can, first of all, more accurately assess the preferences of financial services consumers, make products more personalised, make more accurate assessments of risks and improve compliance and anti-money laundering and combating the financing of terrorism (AML/ CFT) procedures. However, the use of big data may pose a number of risks, including systemic risks for the financial market. Systemic risks may be associated with model risks that can lead to a mass incorrect assessment of the financial situation of borrowers, risks of consumer discrimination (price and non-price), risks of distortion of competition, risks of critical concentration of data providers (including foreign ones) and risks of major leaks of personal data. In this respect, in recent years in different countries, questions of regulating the use of big data by the financial sector have been raised. This report describes the trends in the use of big data globally and in Russia and analyses the benefits and risks of its use as well as potential approaches to limiting the risks of using big data in Russia, including on the basis of foreign regulatory practices. However, this report does not cover the matters of using and protecting personal data in detail.