NEW YORK — Investors rushed back into stocks as profits at a handful of companies indicated the economy might be gaining strength.

Homebuilders and retailers led a broad rally Thursday. The Dow Jones industrial average surged 172 points after four days of losses. The price of government debt jumped after an auction drew strong demand.

The day began with better-than-expected earnings reports. Lennar Corp.’s orders for new homes jumped 63 percent during the second quarter and its revenue beat expectations. And retailers jumped following a report from Bed Bath & Beyond Inc. The home furnishings store said its fiscal first-quarter earnings climbed 14 percent as sales rose following the liquidation of rival Linens N Things.

The Dow rose 172.54, or 2.1 percent, to 8,472.40, after falling 40 points in the early going. It was the biggest point and percentage gain for the blue chips since June 1, though the Dow is still down 67 points for the week. The broader Standard & Poor’s 500 index rose 19.32, or 2.1 percent, to 920.26. The gain pushed the index back into the black for the year.

The Nasdaq composite index rose 37.20, or 2.1 percent, to 1,829.54.

The Dow remains up 29.4 percent from a 12-year low on March 9, but down nearly 330 points, or 3.7 percent, from a five-month high on June 12.