Since the financial crisis, investment grade corporate bond trading volumes have almost doubled. 2017 volumes are projected to total $4.1 trillion, compared to $2.1 trillion in 2007. However this doesn’t tell the whole story – the size of the overall market has tripled over this time period. As a result, liquidity, measured as volumes relative to the overall market, is down quite meaningfully. Today’s chart shows that volumes currently represent 86% of the market while in 2007 they came in at over 120%. This steady decline is due to numerous factors, but a large contributor is the increased regulatory oversight, most notably the Volcker rule which has limited bank investment capabilities.