WASHINGTON (Reuters) - The U.S. Commodity Futures Trading Commission (CFTC) is “closely monitoring” recent activity in silver markets, the agency’s acting chairman said on Monday as last week’s volatility in securities markets spilled into trading of the precious metal. Silver prices surged to their highest in eight years as retail investors piled into the market and posts multiplied on the same Reddit message board behind last week’s frenzied buying of GameStop Corp shares. The CFTC “is communicating with fellow regulators, the exchanges, and stakeholders to address any potential threats to the integrity of the derivatives markets for silver, and remains vigilant in surveilling these markets for fraud and manipulation,” acting chairman Rostin Behnam said in a statement. Surging prices of GameStop, which saw a near 400% gain last week, and other hot stocks have prompted the White House, the top federal securities regulator and state attorneys general to say they are monitoring the situation.