Just caught USIG dipping below a key technical level on the charts. The iShares Broad USD Investment Grade Corporate Bond ETF broke through its 200-day moving average, which had been holding around $51.71. Shares dropped as low as $51.57, so we're talking a pretty clean break here. Currently down about 0.4% for the session. What caught my attention is how this moving average had been acting as support. Looking at the bigger picture, USIG's been trading in a fairly defined range over the past year - low point sits at $49.10 and the high is up around $52.72. So this dip below the moving average is worth watching to see if it signals further weakness or just a pullback. Last I checked it was hovering near $51.72. These technical breakdowns can sometimes lead to retest of lower support levels, so traders watching this moving average breakdown might be setting alerts lower. Interesting to see how this develops over the next few sessions.