Retail, biotech and financial stocks helped push up the Dow Jones Industrial Average last Friday after a midweek tumble. Meanwhile, trading of marketing-services companies' stocks increased at week's end as well. On the Big Board, Omnicom shares rose 2.5 percent to $73.97; IPG gained 2.3 percent to close at $13.40; and British holding company WPP, trading as American Depository Receipts on the Nasdaq, climbed 3.9 percent to $42.03. Merrill Lynch, looking at the ad market at the end of the second quarter, issued an upbeat prognosis: "U.S. media continues to improve, so it is not a stretch to assume that agency activity will follow in good stride. Increased net new-business activity would also indicate improved momentum."