The relevance of this research is caused by the need of strengthening a role of monetary regulators to prevent financial bubbles in the financial markets. The aim of the article is the analysis of a problem of crisis phenomena in the markets of financial assets owing to an inadequate growth of their cost, owing to subjective reasons. The leading approach to mechanism research of crisis phenomena in the market of financial assets is the approach based on a balance effect. Results: authors developed offers to prevent the crisis phenomena in the financial markets due to credit expansion. There is proved the necessity to develop a risk assessment system on existing and new financial instruments, with their obligatory application by commercial banks and rating agencies. The materials of the article can be useful at further studying the reasons for financial bubbles, development of actions for their prevention, and also in an educational process when studying certain subjects.