0.1 BTC is too little to even consider any kind of investment, what you should do is look for ways to earn more bitcoin, signature campaigns, offering your skills to the community for bitcoin or get a job, earn fiat and buy bitcoin with it.
if you are rich or if you want to do a huge thing then it is small but in any case, if you want to make an investment like for example if you want to start trading 0.1
BTC is more than enough. it is $60 at the current rate and i say it is a pretty good amount to start trading because it is big enough to make profit on and small enough to be able to risk it.