Stockbridge Partners has filed a 13G with the SEC regarding shares of Advanced Drainage Systems (WMS). Per the filing, Stockbridge now owns 6.9% of the company with over 3.66 million shares. This is up from the 2.86 million shares they owned at the end of the second quarter. The filing was made due to activity on August 18th. Read more:http://www.marketfolly.com/2015/08/stockbridge-partners-incr...