Material stocks have not been basic
Basic material stocks saw a big cluster of interest on Wednesday, and it was enough to push more than 60% of them to a fresh 52-week high, the most in more than 20 years.
The Backtest Engine shows that other times more than half the stocks hit a new high on the same day, XLB tended to pull back at some point over the short- to medium-term.
Another potential issue is that the surge didn't come gradually, it happened all at once, pushing a huge majority of the stocks outside their upper volatility bands. Again, a jump like this in a normally staid sector has led to more negative returns than positive ones.

