A US jury on Monday found Theranos founder Elizabeth Holmes guilty of defrauding investors in the blood testing startup, convicting her on four of 11 counts.

Holmes was convicted of investor fraud and conspiracy, but acquitted on three counts of defrauding patients who paid for tests from Theranos, and a related conspiracy charge. The jury could not reach a decision on three counts related to other, individual investors.

Holmes, wearing a grey suit, appeared poised after the verdict was read. A sentencing date was not immediately set.

Prosecutors said Holmes, 37, swindled private investors between 2010 and 2015 by convincing them that Theranos’ small machines could run a range of tests on just a single drop of blood from a finger prick.

Holmes rose to Silicon Valley fame after founding Theranos in 2003 at age 19 and became known for her penchant for wearing Steve Jobs-like black turtlenecks. She attracted both high-profile wealthy investors including media mogul Rupert Murdoch and high-profile board members. Her net worth was estimated at $4.5 billion by Forbes in 2015.

She faces up to 80 years in prison when sentenced by US district judge Edward Davila but will likely get a much lower sentence.

Holmes was also charged with misleading patients about the tests’ accuracy but was acquitted of those charges.

Holmes is likely to appeal, but her attorneys and a spokesperson for prosecutors did not respond to requests for comment on Monday. The jury’s verdict came after seven days of deliberations.

The case shed light on Theranos’ failed endeavour to revolutionise lab testing. The company secretly relied on conventional machines manufactured by Siemens to run patients’ tests, prosecutors said.

Theranos collapsed after the Wall Street Journal published a series of articles that suggested its devices were inaccurate. Holmes was indicted in 2018 alongside Theranos’ former chief operating officer Ramesh “Sunny” Balwani, who had also been her romantic partner.