Even as a possible sale of venerable investment bank Lehman Brothers was being coordinated last night, foreshadowing another blow to Wall Street, global investors fleeing the turmoil were flocking to a surprising safe haven: the American dollar.

After lingering in the doldrums for years, the greenback reached a one-year high of $1.40 against the euro yesterday, a surge of 12% in the past two months. Dollar experts said this move portends a monumental shift in the currency to a period of strength from years of weakness. Meanwhile, as the dollar strengthens, gold is getting cheaper: The yellow metal dipped to a one-year low yesterday of $745.50 an ounce.

“Based on the average length of the currency cycle, I would say we have just ended seven years of dollar weakness and are now looking at seven years of dollar strength,” a senior currency strategist at Deutsche Bank, Adam Boyton, said. Before the dollar began its upward march in mid-July, it was 20% undervalued, he estimated.

The rise in the dollar is good news for America because exports are an important contributor to economic growth, according to a senior finance fellow at the Milken Institute, James Barth, who was the chief economist of the Office of Thrift Supervision under President Reagan and the first President Bush. In addition, a strong dollar is likely to translate into lower gas prices, a boon for consumers.

“The dollar has been one of the only beneficiaries of safe haven flows,” a senior market analyst at Heritage West Financial, Ralph Preston, said. “All of this money is being repatriated into the states en masse, causing the dollar to go hyperbolic.”

Driving the bullish dollar sentiment are investors who are fearful the economies of Europe and Asia are touching on a recession, while America’s troubles are nearing the bottom, market watchers said.

“The Federal Reserve has been criticized for not cutting rates sooner, but in fact, they may have proven they were ahead of the curve — cutting rates and stopping when it became inflationary, getting America out of the woods first while the rest of the world is just entering the woods,” a senior analyst at Kitco Bullion Dealers, Jon Nadler, said.

Other reasons for a stronger dollar include the wave of investors who, wary of Capitol Hill’s attacks on speculators, are pulling out of commodities and parking their profits in cash. Also, lower oil prices — some $40 billion has pulled out of the oil markets in the past 60 days, driving light, sweet crude down to $100.87 a barrel yesterday — mean oil-producing countries are collecting fewer dollars.

“There was a lot of concern about dumping of dollars because oil-producing countries were putting up their dollar reserves, but now that oil prices are coming down, the accumulation of dollars by these countries is decelerating,” Mr. Barth said.

As for gold, investors who bought the metal as a hedge against inflation are now selling their positions as oil prices drop, while some investors are simply shedding gold as a profit-taking measure. Some hedge funds, suffering from losses on Wall Street, are also liquidating their gold positions as a way to increase cash holdings and strengthen their bottom lines.

“A lot of hedge funds need to shore up their balance sheets because of bets they took on financial stocks, and so must liquidate their positions elsewhere,” a gold analyst at Deutsche Bank, Joel Crane, said. “One of the easiest ways to do this is to sell a physical commodity, like gold.”

Still, some dollar watchers said that much of the gains have now occurred, and they now expect the dollar to proceed sideways for the remainder of the year.

“The dollar’s surge hasn’t been just a move against the euro — it’s been strong against the British pound, and the New Zealand and Australian currency,” Mr. Boyton said. “But now, we are at the point where I expect the dollar to consolidate, and end the year at $1.35 against the euro.”