On Friday, US stocks closed out January on a down note. For the month, the Dow slid 5.3 percent, the S&P 500 3.6 percent, and the Nasdaq 1.7 percent. Concerns about the global economy and earnings, as well as turmoil in emerging markets, led the Dow to its worst start since 2009. But investors shouldn’t panic yet, money managers say. They will get the January jobs report this week. Also, another 93 members of the S&P 500 are scheduled to report earnings. While fourth-quarter earnings are up 7.9 percent from a year earlier, companies have been cutting their full-year outlooks and reporting weaker sales, according to data provider FactSet.