The stock market started the new week on a positive note Monday, although some selling crept in after the first 10 minutes of trading. Investors await key economic data midweek. X The Nasdaq gained 0.6% in morning stock market action. It had been up as much as 1% before indexes faded from an opening burst. The Dow Jones Industrial Average climbed 0.4%, while the S&P 500 rose 0.5%. All three major indexes are below their 50-day moving averages. The small-cap Russell 2000 crept up 0.3% and is also below its 50-day line, but is on track to end a four-day...