A burst of hiring in February pushed stocks higher. The Dow surpassed its previous record close Tuesday and logged a sixth straight increase Friday. Employers added 236,000 jobs, and the jobless rate fell to 7.7 percent, from 7.9 percent in January. That’s better than the 156,000 job gains and unemployment rate of 7.8 percent that economists expected. Optimism that hiring is picking up has been one of the factors bolstering the market. Stocks have also gained on news that the housing market is recovering, growing corporate earnings, and continuing economic stimulus from the Fed. The Dow is up 9.9 percent this year; the S&P 500 is up 8.8 percent.