$OA is one of biggest losers #stocks today. read more:

Orbital ATK, Inc. Common Stock (symbol: OA) was one of the worst losers of
the trading day today (2016-08-10), losing -20.25%. The number of shares
that changed hands was 8,706,393, or about 21 times the average daily
volume in the stock.
The closing price was $70.79, amounting to a market cap of $4,150,000,000,
about -25.42% off the highest price in the last 12 months. The stock has
been trading at a range between $56.06 and $94.92.
OA is in the Military/Government/Technical industry, part of the Capital
Goods sector.
Looking at its valuation, the stock is now trading at 13.19 times earnings.