Ex-Theranos CEO Elizabeth Holmes testifies in her own defense

Elizabeth Holmes today continued testifying in her criminal fraud trial, after unexpectedly taking the stand in her own defense on Friday.

The latest: The former Theranos CEO sought to undermine prosecutor claims that she lied to prospective investors about the blood testing company's work with drug makers.

• Her basic message seems to be: I had at least some reason to believe what I was sharing was true, even if it wasn't actually true.

The stakes: Holmes, who once was the toast of Silicon Valley, could face up to 20 years in prison if convicted.

The scene: Today's hearing was abbreviated after beginning late for undisclosed reasons, even though Holmes was at the San Jose, Calif. courthouse on time, and she'll still be on the stand when proceedings resume on Tuesday.

The bottom line: The defense is rolling some big dice by putting their client on the stand. Either they believe Holmes can come across as more credible than prosecution witnesses, thus winning over the jury, or they feel they have no other choice.