This figure shows a graph of time on the bottom axis and stock price on the vertical axis. It shows stock price variations over time for three different stocks: ORCL, BOFA, and CWD. Between days 1 and 9 and between days 12 and 19 there is a W-shaped change in stock price for BOFA. That is a fall (labeled X), a rise (labeled Y), a fall (labeled W), and a rise (labeled Z).