Leaders continued to get hit hard Wednesday as volume grew across the board. The Dow fell 1.2%, the S&P 500 2.0%, the NYSE composite 2.4% and the Nasdaq 2.7%. For-profit educator Apollo Group (APOL) tanked 12.90, or 18%, to 60.07. The Securities & Exchange Commission is probing the company's revenue-recognition practices. CNinsure (CISG) dived below its 50-day moving average, dropping 2.25 to 18.50. The Chinese property and casualty insurer has