SMH/SOXL -semiconductors not represented, historically a leading group in market turning points
ARKK - ARK ETF, actively used for hedging by large players. Can be a leading indicator for bounces or selloffs in tech speculation.
SARK -ETF for inverse of ARKK, used to short ARK innovation holdings.
VIXY - VXX is no longer reliable due to changes by Barclays, thus would like VIXY.