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

United States Steel Corporation (symbol: X) was one of the worst losers of
the trading day today (2016-08-12), losing -7.14%. The number of shares
that changed hands was 21,067,532, or about 1 times the average daily
volume in the stock.
The closing price was $21.06, amounting to a market cap of $3,090,000,000,
about -23.81% off the highest price in the last 12 months. The stock has
been trading at a range between $6.15 and $27.64.
X is in the Steel/Iron Ore industry, part of the Basic Industries sector.