Stock futures dug into moderate losses ahead of Tuesday’s open after volatile overnight trade. Dow futures traded 46.4 points below fair market value and were falling. Nasdaq 100 futures fell 13.8 points, and S&P 500 futures were off 7.2 points. Small caps were particularly weak, with Russell 2000 futures down 7.6 points. Friday’s looming deadline for a debt payment from Greece to its eurozone creditors hangs over the stock market today.