I have only a meager amount to be invested , around 0.1 BTC.
There is so much legal issues right now surrounding bitcoin stock exchanges that nothing is low-risk.
Bitcoin itself is considered high-risk by lay-people. Add an un-regulated exchange, plus unregulated security, spells recipe for losing your coins.
So you have Bitcoin -> High-risk
unregulated exchange based on bitcoin -> higher risk
unregulated security held at an unregulated exchange based on high-risk bitcoin -> highest risk
From my experience, your best bet is just to hold onto every bitcoin you can get. The coins you hold will appreciate the most.