In trading on Thursday, shares of the iShares U.S. Basic Materials ETF ( IYM) crossed below their 200 day moving average of $84.31, changing hands as low as $84.03 per share. iShares U.S. Basic Materials shares are currently trading down about 0.5% on the day. The chart below shows the one year performance of IYM shares, versus its 200 day moving average:Looking at the chart above, IYM's low point in its 52 week range is $76.12 per share, with $89.46 as the 52 week high point — that compares with a last trade of $84.20.