The Martha Stewart and Mark Cuban cases were more or less the same -- a non-insider investor was given information from an insider, sold their stock to avoid a loss, and were then investigated for it.

The thing is - insider trading is illegal but it's poorly defined.

Martha Stewart wasn't convicted of insider trading - she was convicted of conspiracy, obstruction of justice, and making false statements to a federal investigator.

Mark Cuban wasn't convicted of insider trading either. He wasn't convicted at all. He kept his mouth shut and the jury found him not guilty of insider trading.

She was sent to prison for lying and trying to cover up her insider trading. If she had just admitted and accepted the punishment, it would have been just a financial penalty.

Her blunder was thinking she was too special (or too rich?... she wasn't really that rich) to have to deal with the laws, so she tried to scheme her way around the punishment.

As I recall, her insider trade only made or saved her something like $64k. That's laughably small, and the final punishment to her would have been little more than a slap on the wrist had she not blown it up by lying and cheating to avoid the original punishment.

I hear this a lot, but she did deserve to be punished. Her defense tried to act like she innocently and accidentally sold some stock based on something a friend told her, but they neglect to mention that she her career started as a stock broker and as such should have been familiar with regulations, and she was on the New York Stock Exchange’s board of directors during the scandal.

It's not some innocent mom who accidentally listened to some advice, she really should have known better.