In the later stages of a Greater Fool type rally, the microcaps get bid up a lot (they were absolutely nuts in early 2000). Since the BPCOMPQ is just an unweighted percentage of the Naz stocks, the speculation in the micros may have a lot to do with the fact that it just keeps going higher...
Zeev: Yes, but BPNDX has lead the way down at least over the past few years. BOCOMPQ has lagged in crossing well after the che composite has made a top the past few years fwiw.