Mumbai, Sept. 17 -- COMEX copper futures are holding relatively flat around $6.50 per pound mark as gains are seen capped by firm dollar after Fed hiked benchmark interest rates. The Federal Open Market Committee (FOMC) voted unanimously to lift the benchmark federal funds rate to a range of 3.75% to 4.0% on Wednesday. It was the US central bank's first rate hike since July 2023. Dollar regained momentum above 100 mark. Meanwhile, stocks on Wall Street came under and pulled back well off their highs of the session and into negative territory. The Dow led the way lower, slumping 631.21 points or 1.2 percent to a three-month closing low of 51,461.90. The S&P 500 fell 33.92 points or 0.5 percent to 7,551.81, its lowest closing level in well ov...