Credit rating announcements, trading activity and yield spreads: the Spanish evidence

We test whether different rating announcements contain pricing-relevant information and modify trading activity patterns in the Spanish corporate debt markets. We observe a significant widening of yield spreads in short- and long-term corporate debt after reviews of downgrades and negative outlook reports. Additionally, certain rating announcements encourage trading activity even when the information is not pricing-relevant. The release of information arouses investor interest for the involved securities. Thus, trading frequency increases, although larger-sized transactions, which should denote possible portfolio rebalancing, are not observed. In the short-term market, trading volumes are found to fade after reviews for downgrade.