Holmes founded the biomedical company in 2003 and helped it become one of the darlings of Silicon Valley. However, after it was revealed that the company provided inaccurate blood tests via its groundbreaking Edison device, Theranos has been on the defensive while under investigation by the U.S. Securities and Exchange Commission and the U.S. Attorney's Office for the Northern District of California.
"Our estimate of Holmes' wealth is based entirely on her 50% stake in Theranos," Forbes wrote in its report. "Forbes spoke to a dozen venture capitalists, analysts, and industry experts, and concluded that a more realistic value for Theranos is $800 million rather than $9 billion. At such a low valuation, Holmes' stake is essentially worth nothing."
Theranos was quick to issue a statement to Times refuting Forbes’s claims. "As a privately held company, we declined to share confidential information with Forbes. As a result, the article was based exclusively on speculation and press reports," said the company's spokeswoman, Brooke Buchanan.
If it is in fact revealed that Holmes's massive $4.5 billion fortune has evaporated, it will mark one of the swiftest falls from grace in recent memory.
For more on Silicon Valley, read Secrets of Silicon Valley: What Everyone Else Can Learn From the Innovation Capital of the World, and let us know if you think Holmes did indeed lose her fortune.