CME Group, the operator of the New York Mercantile Exchange and Commodity Exchange (COMEX), on which silver futures contracts are traded, released a statement to clearing member firms, chief financial officers, back office managers, and margin managers notifying them of an increase in margin requirements “as per the normal review of market volatility to ensure adequate collateral coverage.”

Zero Hedge obtained a copy of the notice, which states that effective after the close of business on November 10, 2010, the maintenance margin requirement for COMEX 5000 Silver Trust Futures (SI) and COMEX 5000 Silver Trade at Settle (SIT) will increase from $5,000 to $6,500 per contract.

Speculation has arisen that this news is responsible for this afternoon’s significant negative reversal in the price of silver.  While silver did tumble shortly before release of the CME’s notice, keep in mind that it had climbed considerably in recent weeks and may have anyways been due for at least a short-term correction.  Nonetheless, the timing of the market’s response is somewhat suspicious.