Are you happy with the rollout of this feature?  So far it does not appear to have led to investors moving coins off site to minimize counter party risk.  JD shows as invested as 5 times the total amount of clams that have been dug. 

I'm thinking some of your investors are not being totally honest about how many coins they have!     I realize you have safeguards in place, but it does look weird.  It seems that your investors got caught in an interesting situation, face dilution on their investment or be compelled to claim to have more coins than they really do.

I'd say the first real test will be when a high roller wins, but given that gamblers actually have to have the coins, while investors need only 1%, and how thinly traded the CLAM market is (since 70% of the actually dug up clams are already invested on JD), I don't think high rollers of the scale you've seen in the past are likely unless a major investor (or you) gets really bored.

Good Luck!