A CITIC Securities research note said the U.S. dollar index has strengthened rapidly in recent days, pushing gold below $4,000 per ounce.

According to ChainCatcher, the note said easing inflation concerns have not led to a weaker dollar.

CITIC Securities attributed the dollar’s recent strength partly to political “re-dollarization,” but said the more important driver is expectations of tighter U.S. dollar liquidity.

The firm expects the dollar index to remain supported this year but said it may be difficult for it to sustain further sharp gains. It added that the next U.S. inflation data release could act as a catalyst for markets to adjust their trading approach.