NEW YORK ( TheStreet) -- Permanent Portfolio ( PRPFX) has enjoyed a remarkable run. During the past ten years, the mutual fund returned 11% annually, ranking as the top-returning competitor in Morningstar's conservative allocation category. The number two fund lagged Permanent Portfolio by 3 percentage points, while the S&P 500 trailed by 7 percentage points.Seeing the compelling results, investors have poured into the fund. Permanent Portfolio's assets climbed from $333 million in 2005 to $17.2 billion now. But the new shareholders are not likely to be pleased with their investment. After enjoying an epic hot streak, the fund seems likely to be faced with a period of mediocre results. The problem is that the fund depends heavily on Treasuries, precious metals and Swiss francs -- assets that could be peaking after long rallies.