The USD/JPY is under renewed selling pressure today, emerging as one of the market's biggest movers with a decline of nearly 0.50%. As broad USD strength wanes, the pair has retreated to a "make-or-break" technical junction that has defined the trend for nearly a month.The 100-Hour Moving Average: A Line in the SandSince February 11, the rising 100-hour Moving Average (MA) has served as a reliable guide for the USD/JPY uptrend. Buyers have consistently stepped in at this level to defend the pair's trajectory, most notably during the late-week lows of the previous session.Earlier today, the pair bottomed exactly at this MA, sparking a brief bounce toward 157.41. However, that recovery lost steam just shy of the primary topside resistance zone between 157.65 and 157.73.Current Technical OutlookThe price is currently retesting the 100-hour MA at 156.87. This level serves as the current barometer for market sentiment:The Bullish Defense: If the price manages to hold above 156.87, the buyers remain technically in control, keeping the door open for another run at the 157.70 resistance area.The Bearish Break: A sustained move below this moving average would signal that "sellers are banging on the door." If support fails here, expect a shift in bias as buyers pull back, likely exposing the 200-hour Moving Average at 156.17 as the next major downside target. This article was written by Greg Michalowski at investinglive.com.