Cross Market Effects of stocks Short-Selling Restrictions: Evidence from the September 2008 Natural Experiment

Using intraday data, this paper investigates empirically the joint stock and corporate bond markets responses to the September 2008 stocks short sell ban. The study intends to exploit the natural experiment in order to asses the impact of the stock market short sale restrictions (stock market liquidity shock) on corporate bond market variables during the financial crisis period. The short sell ban was one of the levers that regulators pulled in order to manage the financial crisis. The economic question is whether this lever worked or should have been pulled given the complexity of financial market linkages and news dissemination. Recent financial events suggested that, when market conditions are severe, liquidity can rapidly decline or even disappear. Liquidity shocks are the potential channel through which asset prices are influenced by liquidity. However, the standard theoretical equilibrium asset pricing models do not consider trading and thus ignore the time and cost of transforming cash into financial assets and viceversa hence ignoring the impact of the liquidity shocks. Therefore, investigating liquidity shocks empirically, their transmission across markets is of high interest especially during times of high turbulence as we recently witnessed. We use vector autoregression (VAR) approach to model stock and corporate bond returns, volatilities and transaction costs simultaneously, obtaining an econometric reduced form that incorporates causal and feedback effects among the two markets variables. Using VAR tools, we found that shocks in stock market (short sell ban) had a significant negative impact on corporate bond market variables during the time under investigation.