Large Cap Showing Slightly More Divergence Than Mid & Small Cap

Constituents above 50MA & YTD price returns:
Large-Cap: 62%, Up 20%
Mid-Cap: 65%, Up 17%
Small-Cap: 61%, Up 20%

It makes sense that large-caps are expressing the largest divergence between returns & constituents given the concentration of the index and no upper market-cap bound.

Large-Cap SPY
Mid-Cap MDY
Small-Cap AMEX:SLY