One of the first things I ever noticed while charting is that both oversold of RSI (14) nearing 30 and overbought RSI (14) nearing 70 generally lead to corrections. Overlay charts that show that along with contrarian indicators like the CPC or VIX and you can anticipate both rallies and sell offs.
I posted these charts because the market is in a position to rally here. The recent selling was harder on the NYSE and S&P 500 than the SOX and NASDAQ so I look for tech stocks to lead if they will. Of course rallies do end at some point but as we have already discussed now would be a historically fast end to a cyclical rally after a recession.