Beaten-down homebuilder stocks got a boost Friday after a rumor floated around that Warren Buffett is buying shares of

Hovnanian

(HOV) - Get Report

.

Berkshire Hathaway

(BRK.A) - Get Report

, the investment vehicle of Buffett, is known to buy stocks on the cheap. The firm declined to comment on the rumor, saying its long-standing policy is to never discuss its investment activities except when it is legally required to do so.

Two sources who closely follow the homebuilding industry said they would be surprised if the rumor turned out to be true.

"

Buffett was never involved in past. I don't think he would get involved now," says one sell-side analyst.

A hedge fund source also expressed skepticism. "Housing has not bottomed yet, so why would he buy now?" he says.

Nonetheless, the rumor lifted nearly all homebuilder stocks. Hovnanian shares were up $1.47, or 8.8%, to $18.02. The company didn't immediately return a call seeking comment.

Brookfield Homes

( BHS) jumped 5.1% to $29.65;

Centex

(CTX)

added 4.4% to $43.45;

NVR

(NVR) - Get Report

climbed 4.4% to 710.13; and

Toll Brothers

(TOL) - Get Report

rose 3.7% to $26.41.

"I think it's still too early to start buying the stocks, given that we are barely starting to see the tip of the iceberg in terms of foreclosures, and the biggest impairment charges are still ahead of us," says Alex Barron, an analyst with Agency Trading Group.