Arthur Hill over at StockCharts.com put a really important chart up this morning. The high yield bond market has been positively correlated with US Stocks for some time now. So a breakdown in this area is a negative for the stock market.
This chart shows the High Yield Bond ETF ($JNK) breaking below key support. Not shown here, you can also draw trendlines from the January lows and those uptrends are now broken as well.
Arthur Hill did a nice job of highlighting the December highs which also coincide with the highs from October. This former resistance could become the first support zone for $JNK.