NEW YORK ( TheStreet) -- U.S. stocks closed higher Friday as Federal Reserve Chairman Ben Bernanke signaled a continuation of monetary support for a U.S. economic recovery. The S&P 500 tacked on 0.43% to 1,633.70, and gained 1.19% for the week. "It just doesn't seem like a market that wants to lie over and play dead," said Marty Leclerc, chief investment officer at Barrack Yard Advisors. "Clearly we're closer to the end of something than the beginning of something but how long this end-phase can last is anyone's guess." Bernanke, in a speech this morning at a Federal Reserve Bank of Chicago-sponsored conference, said the Fed is closely monitoring the asset markets for any instances of "reaching for yield" and other forms of excessive risk-taking that could destabilize asset prices and that it continues to watch out for remaining vulnerabilities in the shadow banking sector. Commodities dropped as the dollar strengthened to a four-year-high. June crude oil contracts closed down 35 cents to $96.04 a barrel and gold futures plunged $32 to settle at $1,436.60 an ounce. "The strong dollar is going to give the market a bit of a bit of indigestion," said Peter Cardillo, chief market economist at Rockwell Global Capital in New York. "The stronger dollar is weighing on risk. We're not at levels where we have to worry about exports falling apart, but certainly as the dollar gets stronger, it is a bit of negative on the market." The U.S. dollar index was up ahead by 0.58% to $83.17 in afternoon trades and booked a four-year high against the Japanese yen as the currency breached the 100 yen to U.S. dollar mark for the first time since April 2009 as investors became more optimistic about the U.S. economy after strong reports on the U.S. labor market. The Dow Jones Industrial Average was up 0.2% to 15,118.49. The blue-chip index added 1% for the week. The Nasdaq closed up 0.8% to 3,436.58. The tech-heavy index jumped 1.7% for the week. Actavis ( ACT) was the top performing stock on the S&P after the generic drug maker said it was in early discussions to buy Warner Chilcott, according to a Bloomberg report. Shares of the company jumped 12% to $119.86.