A significant insider transaction involving the exercise of company stock options was reported on August 28, by LEROY BALL, CEO at Koppers Hldgs (NYSE:KOP), as per the latest SEC filing. What Happened: A Form 4 filing from the U.S. Securities and Exchange Commission on Wednesday showed that BALL, CEO at Koppers Hldgs, a company in the Materials sector, just exercised stock options worth 4,000 shares of KOP stock with an exercise price of $17.57. The Thursday morning market activity shows Koppers Hldgs shares down by 0.0%, trading at $38.72. This implies a total value of $84,600 for BALL’s 4,00…