DXY weights: euro 57.6%, yen 13.6%, pound 11.9%, Canadian dollar 9.1%, krona 4.2%, franc 3.6%. When DXY rises, most major-pairs quoted as XXX/USD fall.
Dollar strength affects more than forex. gc and other commodities priced in dollars tend to move inversely to it, and a strong dollar tightens conditions for emerging markets.
Example: DXY rises from 103 to 106 (2.9%) over a month. EUR/USD, its largest component, falls from 1.09 to 1.05 over the same period.
Related: major-pairs, gc, federal-funds-rate, risk-on-risk-off