Semiconductors and oil service stocks cross over late in the cycle since Semis are the earliest cyclicals whereas oil service are late cycle. The "signal" worked flawlessly ahead of Lehman in 2008.
The red line is the Semioconductor ETF Minus the Oil Services ETF - to indicate relative strength inflection points, like the one that occurred in July 2008 and the one that occurred this past July 2014. The crossover signal worked in 2011 as well...
Profits Now. Apocalypse Pending.