Is the US headed toward a new housing bubble?

The staggering rise of U.S. home prices is forcing thousands of aspiring buyers into grueling, often risky bidding wars, raising questions about whether the torrid housing market could be in a bubble.

For nearly a year, the combination of low mortgage rates, a flood federal stimulus, lockdowns and teleworking — all sparked by the coronavirus pandemic — has fueled a rapid increase in demand for houses.

At the same time, COVID-19 exacerbated an already severe housing shortfall by causing major delays in new home construction and kept some potential sellers...