LOS ANGELES — Bidding wars sound almost quaint. These days, the only way for would-be buyers to secure a home, it often seems, is to offer all cash and be ready to do so within hours, not days.

The bursting of last decade’s housing bubble feels like ancient history here, where first-time home buyers are competing with investors to get into single-family homes with prices approaching $1 million.

“It’s everyone from a kid out of law school to an investor from China, walking around with thousands to spend,” said Kameron Eliassian, a Los Angeles real estate agent. “I don’t know where it’s coming from, and I don’t care. Just show me proof that it’s there, and we’re good.”

After saving money for years, waiting for the residential real estate market to hit bottom, buyers all over the country appear eager to get back in, lured by low interest rates and the prospect of a good deal.

But with the number of homes for sale at historically low levels and large investors purchasing thousands of properties, buyers are facing a radically changed market and prices are quickly rising.