NEW YORK -- With the Dow Jones industrials and Standard & Poor's 500 index hitting multiyear highs four straight days last week, many on Wall Street are beginning to wonder whether this rally has the fortitude to make a serious run even higher.

Last week, the major indexes rallied substantially as investors saw evidence of low inflation and moderate economic growth -- the right recipe for the Federal Reserve to stop raising interest rates, and for corporate America to continue increasing profits. As a result, the Dow gained 1.84 percent; the S&P rose 2 percent; and the Nasdaq composite index jumped 1.96 percent for the week.

Investors have shown a strong bias toward buying stocks right now, believing that, at least for the short term, there's room to go even higher. However, investors in this current market are quick to sell off if there's any kind of signal that the balance between inflation, economic growth and the Fed is off-kilter.

Certainly, caution will take over at some point, especially with the Fed meeting March 28. As the meeting draws closer, some investors will certainly want to collect profits after last week's rally. The Fed is widely expected to raise interest rates by a quarter percentage point.

Economic data

Nonetheless, the week's meager slate of economic reports contain two items that could move the markets. On Tuesday, the Labor Department releases February's producer price index, which measures price increases on the wholesale and industrial level. PPI was expected to fall 0.2 percent for February, far better than the 0.3 percent hike in wholesale prices in January.

So-called core PPI, with food and fuel prices removed due to their volatility, was expected to rise a modest 0.2 percent in February, down from 0.4 percent the previous month. If the PPI figures are lower than expected, the rally could gain fresh momentum. If not, the market bulls will have a hard time charging through it.

On Friday, the Commerce Department releases its report on orders for durable goods, big-ticket manufactured items designed to last at least three years. For February, durable goods orders were expected to rise 1 percent after a 9.9 percent drop in January. Investors might like a lower-than-expected number, which would illustrate a slowing economy that would make it harder for the Fed to raise rates.

Earnings

The start of first-quarter earnings season is weeks away, but there are a handful of notable companies reporting results in the week ahead.

With Goldman Sachs Group Inc., Lehman Brothers Holdings Inc. and Bear Stearns Cos. all reporting record first-quarter revenue and profits last weeks, investors will be looking to Morgan Stanley for a clean sweep.

Morgan Stanley is expected to earn $1.25 per share for the quarter, up from $1.19 per share a year ago, when it reports Wednesday morning. The company's stock is up 26.4 percent from its 52-week low of $47.66 on May 13, 2005, closing Friday at $60.26.