What is an example of EWS?

Could you please provide an illustrative instance of what an Early Warning System (EWS) might entail in the realm of cryptocurrency and finance? Perhaps you could walk us through a scenario where an EWS was successfully utilized to mitigate potential risks or avert a financial crisis within the crypto market? I'm particularly interested in understanding how such a system operates and the specific metrics or indicators it monitors to keep investors and stakeholders informed and prepared.