On April 24th, the SEC provided notice of NYSE Arca's filing of a proposed amendment to NYSE Arca Equities Rule 7.31(a) to add a Moving Average Check that would prevent incoming Market Orders and marketable Limit Orders, as defined in NYSE Arca Equities Rule 7.31(b), from trading if the order size exceeded certain thresholds. The Exchange believes that the proposed Moving Average Check would serve as an additional safeguard that could help limit potential harm from extreme price volatility by preventing executions of potentially erroneously sized orders. Comments should be submitted on or before May 21, 2013. SEC Release No. 34-69443.