The sovereign CDS market has developed rapidly for two decades and currently has a gross notional amount of more than a trillion dollars. We document a strong momentum effect in this market, which cannot be explained by a large set of risk factors. These momentum returns are positively skewed and higher during recessions. Consistent with the interpretation that this momentum effect is due to investors’ initial underreaction to sovereign credit information followed by corrections, our evidence shows that the momentum returns tend to be higher during the months surrounding announcements of credit rating or outlook changes of the underlying countries.

We use the advent of new credit default swap (CDS) trading conventions in April 2009—the CDS Big Bang—to study how a shock to funding liquidity impacts market liquidity. After the Big Bang, traders are required to pay upfront fees to execute CDS transactions, with the size of the fees depending on the level of CDS spreads. While CDS bid-ask spreads decline in aggregate after the Big Bang, they do so less for contracts that require larger fees. Furthermore, the funding effect is stronger for smaller and riskier firms and for noncentrally cleared contracts. The effect also becomes stronger after Deutsche Bank's exit.