Southern Co. (SO) closed the most recent trading day at $66.94, moving -0.01% from the previous trading session. This change lagged the S&P 500's 0.06% gain on the day. Meanwhile, the Dow gained 0.13%, and the Nasdaq, a tech-heavy index, added 0.24%.Heading into today, shares of the power company had lost 6.79% over the past month, lagging the Utilities sector's loss of 5.4% and the S&P 500's gain of 6.45% in that time.Market participants will be closely following the financial results of Southern Co. in it ...