Fear-stricken credit markets have started moving again since the Federal Reserve swooped in with its massive interest rate cut.

A single big deal showed that the healing may have started, but debt markets still could need a long time to recuperate.

This week, Kohlberg Kravis Roberts and some leading banks started selling what could be as much as $10 billion in loans to fund their $30 billion buyout of credit card processing giant First Data Corp.

It's the largest return to the debt markets since the credit crisis started in late summer.