Orange County’s billionaires lost a combined $5.8 billion of wealth since September, according to Forbes.

Forbes on Wednesday announced its list of global billionaires, which counts nine OC residents among the 793 people on its list. That’s down from 1,125 global billionaires a year ago.

None of the nine locals on the Forbes list have seen their wealth increase since mid-September, when Forbes released its ranking of richest Americans.

Donald Bren, chairman and owner of Irvine Company, remains the highest-ranking person from OC on the Forbes list. He’s valued at $12 billion, the same as six months ago.

In August, the Business Journal estimated Bren at $10.5 billion.

Bren now claims the title of richest real estate owner in the world and is the world’s 26th wealthiest person, according to the Forbes list.

Next from OC are David Sun and John Tu, the executives and owners of Fountain Valley-based Kingston Technology Co., at $2.5 billion each. That’s an estimated $1.5 billion drop in wealth for both Sun and Tu since September.

The Business Journal last year estimated Sun and Tu at $2 billion each. We contend Forbes may overvalue the pair by placing too much emphasis on the company’s flash memory business, which generates a higher valuation but only makes up about a fourth of the company’s business.

Jim Jannard, founder of Oakley Inc., is now valued by Forbes at $2.2 billion, a drop from $3 billion in September. The Business Journal pegged Jannard at $1.6 billion last August.

Bill Gross of Newport Beach bond fund manager Pacific Investment Management Co. is listed at $1.9 billion, compared to $2 billion in September. Our latest estimate was $1.3 billion.

Igor Olenicoff, president and owner of Newport Beach-based real estate company Olen Properties Corp., is at $1.4 billion, a $300 million drop from September. Our latest estimate was $1.5 billion.

Real estate owner and businessman George Argyros is listed at $1.3 billion, a half-billion dollar drop from September, according to Forbes. Our latest estimate for Argyros in August was $1.5 billion.

Broadcom Corp. cofounders Henry Samueli and Henry Nicholas are at $1.3 and $1.2 billion, respectively, down from $1.8 billion each in September.