The Canadian Dollar has depreciated roughly 6% against the US Dollar since the beginning of February, as shown in the chart below.
George Davis, award-winning RBC Capital Markets Chief Technical Strategist explains in his March 2018 video report, which can be accessed here, that the weakness in the Canadian Dollar in the first quarter of the year was due to two primary factors:
1. Softer than expected economic data, with Q4 GDP coming in at 1.7% vs the Bank of Canada's forecast of 2.5% growth
2. Increase in trade-related concerns around the "lingering" NAFTA negotiations and the recently introduced tariffs on US imports of steel and aluminum
These factors have created a level of economic uncertainty that forced the Bank of Canada to keep interest rates unchanged in their most recent meeting.
"Trade-related uncertainty is going to persist over the shorter term and that's likely to create downside risk for the Canadian dollar"