(MoneyWatch) Another clanging note from the chorus of voices from the Federal Reserve helped send the Dow Industrials sharply lower Friday.
Richmond Fed president Jeffrey Lacker, a consistent dissenter from the central bank's easy money policies, told a judicial conference that monetary stimulus wasn't in fact doing much to stimulate growth, and that September may be a likely time the Fed would begin rolling it back.
The Dow Jones industrial average fell 114 points to 14,909. The Dow had been down 132 points earlier but also spent much of the day in positive territory. The Nasdaq composite ended up 1 point to 3,403.
"I seriously doubt additional monetary stimulus can provide much impetus to real growth right now," Lacker said in the morning. "But further stimulus does increase the size of our balance sheet and correspondingly increases the risks associated with the exit process when it becomes time to withdraw stimulus."
Lacker also predicted continued volatility in the coming months as investors continue to parse out central bank effects on the economy.
His words were among the latest by Fed officials weighing in -- mostly on the side of convincing investors that stimulus isn't going away soon -- after comments by Fed Chairman Ben Bernanke sent the markets into tailspin.
BlackBerry maker Research In Motion (BBRY) lost 27 percent to $10.46 After staking much of its future prosperity on a new model, it wouldn't disclose how many of the units it has sold, spooking investors.
Recent gyrations were accentuated by end-of-the-quarter buying and selling by funds as they rebalanced their portfolios, known as window dressing.
The yield on the 10-year Treasury bond fell to 2.4 percent.