I don't believe Rosetta Stone is an insider. The 13G had to be filed when greater than 5% ownership was acquired. Although Rosetta's 1.5 million share ownership does throw the 1.5 million float number into question.
Float is sometimes defined differently and the float I quoted was from Yahoo! Finance. I believe Yahoo calculates the float by subtracting all insider ownership from the outstanding shares. I think they just process the all the forms 3, 4, and 5 and come up with a number for insider ownership and then subtract that from outstanding shares. I could be mistaken, though. I've never looked too deeply into it. I know that often Yahoo is mistaken in the numbers they give, either being out of date or by mechanically deriving some of their numbers when doing so is inappropriate.
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