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

Great Plains Energy Incorporate (symbol: GXP) was one of the worst losers
of the trading day today (2016-05-31), losing -5.87%. The number of shares
that changed hands was 12,757,243, or about 8 times the average daily
volume in the stock.
The closing price was $29.18, amounting to a market cap of $4,510,000,000,
about -10.87% off the highest price in the last 12 months. The stock has
been trading at a range between $24.06 and $32.74.
GXP is in the Electric Utilities: Central industry, part of the Public
Utilities sector.
Looking at its valuation, the stock is now trading at 20.56 times earnings.