FXStreet (Edinburgh) - The US Dollar Index, which gauges the greenback vs. its main competitors, is giving away further ground today, testing lows around 97.60. US Dollar challenges post-ECB low The index is testing post-ECB lows recorded last week in the 97.70/60 band following the increasing risk-on trade in the global markets and the poor performance from US Treasuries. In the meantime, USD dollar is retreating for the second session in a row, falling sharply from fresh cycle highs around 100.60 in early December. Ahead in the session, the US docket appears more interesting in light of the releases of Initial Claims tomorrow, and Retail Sales, Producer Prices and the Reuters/Michigan Index all due on Friday. US Dollar significant levels As of writing the US Dollar Index is losing 0.75% at 97.68 with the next support at 97.60 (low post-ECB Dec.3) followed by 96.79 (200-day sma) and finally 95.23 (4-month uptrend). On the flip side, a break above 99.00 (23.6% Fibo of 93.83-100.60) would aim for 100.00 (psychological handle) and finally 100.60 (high Dec.3). For more information, read our latest forex news.