Crude oil futures slumped on Tuesday, pausing from Monday's rally, as China devalued the national currency, raising concerns on demand for oil in the second biggest economy. WTI futures slid 0.73% at $44.63 per barrel, while Brent futures fell 0.60% to $50.11 per barrel. The pressure on oil prices also came from the firmer Greenback and trader's cautious expectations of the US stockpiles figures.