SAN FRANCISCO — Theranos founder Elizabeth Holmes was charged with "massive fraud" by the Securities and Exchange Commission on Wednesday, a downbeat coda to a once high-flying Silicon Valley start-up that promised to revolutionize the blood analysis process. 

The SEC complaint charged that Theranos raised more than $700 million from late 2013 to 2015 while "deceiving investors by making it appear as if Theranos had successfully developed a commercially-ready portable blood analyzer" that could perform a full range of laboratory tests from a small sample of blood.

“But in reality, we allege that after years of development, Theranos was able to process just a small number of blood tests upon its proprietary analyzer, and instead conducted the vast majority of its patients’ tests on modified commercial analyzers that were manufactured by others,” Steven Peikin, the SEC’s co-director of enforcement, told reporters.