I think it is mainly about changes in market sentiments. When stocks got a break earlier this month from declining bond yields, which index led a stock market rally?: It was the (very) interest-rate sensitive Dow Jones. Today, which index is leading the rally?: The growth-sensitive NASDAQ.
The remaining question is why aren't bonds bringing stocks down? The answer is in the yield curve. Short-term maturities -- taking into account the volatility differences between maturities -- have a much smaller propensity to go down than longer maturities because inflation worries have been a much bigger concern than fears of stiff short-term rate hikes since late February.
