This graph aggregate HYG+LQD+JNK and divides by 3 for an average. It then creates a linear regression channel. It also shows some correlation coefficients to OIL, US10Y treasuries, and the Chicago Fed's National Financial Conditions Index. In short, it is about to break the lower bound and it looks like the recovery, even with the Fed's help, is incredibly shaky.
Technical move. Issues from Europe could weigh in on the US banking system. If we got to the situation where there were no bids on JNK, we could see a pretty large collapse in that market. The US banking sector tracks JNK tightly as it is more of an institutional grade investment that banks do not mind holding.