Firm action in US dollar index keeps copper under pressure as the metal pulled back from a one week high. The red metal ended Friday at $4.27 per pound, down nearly 1% on the day. US dollar index holding above 108 mark, hitting one week high has capped gains in the red metal. Meanwhile, choppy end to US equities also weighed on the counter. The major averages on Wall Street finished the day just off their lows of the session. The Dow slid 337.47 points or 0.8 percent to 44,544.66, the S&P 500 fell 30.64 points or 0.5 percent to 6,040.53 and the Nasdaq dipped 54.31 points or 0.3 percent to 19,627.44. For the week, the Dow rose by 0.3 percent, but the S&P 500 slumped by 1.0 percent and the Nasdaq tumbled by 1.6 percent.