If this turns out to be a shakeout I will be very surprised. With an undercut of the follow through day lows and high volume distribution developing on the indexes so close to the follow through day, both of which have historically led to rally failures, you should be moving to cash.
I drew my line in the sand at those lows and have now moved almost to cash. I still have some early buys acting well, but the line in those stocks is now drawn too. No need to give up all the profit.
Today should be a lesson in how quickly one must act in the market, especially aggressive investors.
Back to the drawing board.