One thing I'd love to know, and that might come out in court eventually, is which early investors exited in the huge dumb-money round in 2014. What did they know and when did they know it, and all that.
IANAL, but I'm pretty sure that in this kind of situation, unless said investors have a seat on the board of directors -- and none at Theranos did -- they're almost certainly not in trouble with the SEC.
Theranos is a private company so the SEC rules around MNPI are not relevant here. However, if (IF) any of the earlier investors told later investors things about Theranos that they had reason to doubt in an effort to up the valuation of the next round, then I suppose that might be lawsuit fodder.
Out of interest, does any one know what liabilities such investors might have? If the outside investors had knowledge of the problems we are now seeing and sold off without disclosing the issues, are they somewhat accountable?
That almost entirely binds to what responsibility they had in regards to the company. If they weren't legally insiders, then even if they had more knowledge than the broader public does (which in this case may be irrelevant depending on a few things), they won't be carrying liability.
To be clear, selling doesn't make them liable for fraud committed by Theranos, if they had no role in managing the company. Even if a lawsuit were brought, you're going to have one helluva hurdle in getting any liability to stick to said investor/s without proving direct involvement.
Doing anything about insider trading in a private corporation, has historically been a challenging area for the SEC. They have often previously been more hands off, but they've gotten more aggressive about it lately:
"On December 12, 2011, the SEC announced an enforcement proceeding that serves as a useful reminder that the federal laws against insider trading and misrepresentation apply as forcefully to private companies purchasing stock from employees and other shareholders as they do in the public company setting."