Now i wont say any names on the data provider that is total rubbish and crap and should burn in hell (cough Barclays data services cough cough) it just wouldnt be fair on them.
Bad ticks happen. Look at the center of EWZ's chart:
I have the opinion that bad ticks are a signal that the stock or ETF has bottomed or topped. The bad tick can point up or down. I sometimes act on bad ticks.
Going off my opinion that bad ticks serve as a signal to mark the top or bottom, and can point up or down, notice on the USO chart that the blip you referred to occured one day after the top.
