The Dow Jones industrial average managed to post modest gains on Friday but failed to end the day above 10,000, instead settling for 9,966 following yet another turbulent week. It ended down for the fourth week in a row, losing 0.46 percent. Light afternoon trading took the luster off Saudi Arabia’s claim that it will boost production by 2 million barrels of oil per day. A formal announcement was expected out of Opec meetings this past weekend. High oil prices have continued to drag down world markets. Tech stocks were better, as the Nasdaq ended up slightly. On the Big Board, Omnicom shares remained flat on the week, closing at $79.07; likewise, IPG’s stock price was relatively static over the course of the week but managed an 0.8 percent gain, closing at $14.16. WPP, trading as American Depository Receipts on the Nasdaq, was up 5 percent to finish at $48.95.