Balwani was found guilty of deceiving investors as part of a plot with his ex-girlfriend.
He claimed that Theranos had a device that could detect hundreds of diseases with a small amount of blood.
At a trial in January, she was found guilty of accusing Balwani of abusing her.
A judge will sentence the two men in the fall.
The man is free on bail as he faces 20 years in prison. Balwani could face up to 20 years in prison and millions of dollars in payments to his victims if he is found guilty.
The company was once worth $9 billion but was based on blood testing technology that did not work.
The verdict was read in San Jose on the fifth day of deliberations. He was found guilty of all the charges.
The text messages were shown during closing arguments.
He wrote in 2015 that he was responsible for everything at the company. My decisions have been the same.
The message was an admission of guilt, according to the assistant US attorney. He said that he was acknowledging his part in the fraud.
Theranos used to be a darling of the tech world.
Murdoch and Ellison were billionaires and were able to raise more than $900m.
The firm promised to change the healthcare industry with a test that could detect diseases with a few drops of blood.
The core blood-testing technology did not work according to the Wall Street Journal.
The three-month case against Balwani had a lot in common with the government's prosecution ofHolmes.
Balwani's lawyers argued that he was also deceived by the company after he joined.
The company fell apart in 2016 and the couple went to great lengths to make sure employees and investors didn't know about their relationship.
His lawyers pointed out that he never cashed out his stock options even after investing over a billion dollars into Theranos.
Balwani didn't testify in his defense.
During a college trip to Beijing, the two met.
Before the dot-com bubble burst, he had made millions selling his software company. He divorced his wife around the same time he metHolmes. Around the time that Theranos was being started, their relationship became romantic.
The man who was the face of the company was also the president and COO.
Robert Leach said earlier in the trial that Ms.Holmes and Mr. Balwani were partners in almost everything.
The defendants were aware that the false statements they were making to investors were not true.