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The S&P 400 (mid-cap) and 600 (small cap) have been leading the market higher since the middle of February when the RS analysis turned positive. Both are still acting better than the large-cap indices, but over the past few days, the S&P 600 has given up a bit of its leadership as the RS has dropped below its WMA. No signs yet that either average has topped out, but a drop below the March 22 lows would be a short-term negative.