The DXY measures the performance of the USD versus a basket of six foreign currencies, deriving a geometric mean based on preset weights. Currently the currency with the largest weight (by far) in DXY is the Euro at a whopping 57.6% weight. The currency with the next largest weight is the Yen at a much more meager 13.6% figure.
An alternative measure for the USD is the Fed Reserve's trade-weighted representation (USTWBROA on Bloomberg). It offers a depiction of the USD that takes into account a much broader basket of currencies, currently comprised of 20+ regions and/or countries. And the weights are flatter with the largest weight, China's Yuan, set at 20.8% and the next largest weight, the Euro, at 16.2%.
Over time the DXY and USTWBROA have tracked fairly closely, but as shown below, that's not been the case since the latter half of last year.
Whereas the DXY broke down through a rising trend in the 3Q of 2013, the USTWBROA has maintained its steady ascent within the rising trend. Obviously the strength of the Euro and the variance in composition and weights of the two USD representations have much to do with this fairly recent disconnect. But depending on which measure one chooses to portray the USD, quite a different view can emerge. In the chart above, the DXY appears bearish and yet the USTWBROA appears quite the opposite. Food for thought.