Greek stocks finished the month on a strong note, advancing more than 3 percent, as buyers turned to banks. The Athens Exchange’s benchmark general index rose 3.36 percent to 1,684.37 points, racking up gains of nearly 10 percent for the month in its best monthly performance since August 2003. Trading in banks continued to be volatile, as the sector jumped 6.71 percent. National Bank soared 7.64 percent to 11.41 euros and Alpha Bank rose 6.64 percent to 4.98 euros. The blue chip FTSE/ATHEX 20 index added 4.10 percent to end the session at 846.78 points. Turnover reached 130.8 million euros versus 93.2 million euros in the previous session.