  We propose a new model of the liquidity driven banking system focusing on
overnight interbank loans. This significant branch of the interbank market is
commonly neglected in the banking system modeling and systemic risk analysis.
We construct a model where banks are allowed to use both the interbank and the
securities markets to manage their liquidity demand and supply as driven by
prudential requirements in a volatile environment. The network of interbank
loans is dynamic and simulated every day. We show how only the intrasystem cash
fluctuations, without any external shocks, may lead to systemic defaults, what
may be a symptom of the self-organized criticality of the system. We also
analyze the impact of different prudential regulations and market conditions on
the interbank market resilience. We confirm that central bank's asset purchase
programs, limiting the declines in government bond prices, can successfully
stabilize bank's liquidity demand. The model can be used to analyze the
interbank market impact of macroprudential tools.
