Stocks were down today — breaking a streak of record highs for S&P 500 and Dow Jones Industrial Average — after the U.S. Securities & Exchange Commission revealed a cyber security breach of the Edgar system. Investors also digested the impact of a potential interest rate hike before the end of the year by the Federal Reserve Bank. Edgar is where public companies file quarterly and annual reports, proxy statements, takeover, merger and other documents as well as when executives and major shareholders…