A few tidbits on the US corporate bond market from BofAML:
Summer 2019 snapshot of the US HG market. The US high grade (HG) corporate credit market has expanded to an $8.293tn asset class, including $7.959tn of bonds and $0.334tn of derivatives notional outstanding.
Supply. HG new issuance volumes have averaged $1.258tn per year since 2014, peaking at $1.396tn in 2017 with $1.187tr expected in 2019.