Dollar Cost Averaging in Sliding Stock Market

I am working on story for Advisor News and Insurance News Net on opportunities for dollar cost averaging in sliding stock market. I am interested in: 1. Are their DCA opportunities in this market? 2. If so, what are the best strategies and why? 3. Also, what other opportunistic moves can investors make in a downward stock market – and why? I need DCA experts, investment experts, money managers and financial planners.