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2. Every round has a random return % between 110% to 200%.
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4. Every next player's invest will payout its previous investor and hence only the last person looses.
I dont understand #4 here I think. Lets say its a 200% round (which should double). If we further assume Fixed deposit amounts:
#1 invests 1 - bankroll is 1
#2 invests 1 - bankroll is 2, #1 gets paid 2
#3 invests 1 - bankroll is 1, #2 gets paid 2, where does the missing 1 BTC come from?