Master's Thesis from the year 2016 in the subject Economics - Other, grade: 1,3, University of Siegen, language: English, abstract: Market liquidity is most important for financial markets and thus for the real economy. Market-makers seem to provide less liquidity recently. The reasons of such a behaviour are shown within this work. It exhibits the regulations which have changed, the behaviour of market-makers and how financial markets are able to become illiquid. After this more theoretical framework, which refers to financial stability, several measures of liquidity are introduced and empirically tested on a dataset of about 60,000 corporate and sovereign bonds in 34 countries over a period of eleven years. The result, is that bond markets became less liquid within the last three years than during the financial and the following European debt crisis.