Bitcoins is itself a investment , Its like a share market price up and down Ever Sec . so its depend on you want to invest bitcoins in following -
Invest in trading area
Invest in Bitcoin Faucet (high investment gives high return Experience need)
Invest in btcjam get Flat Return (invest only in Trusted person)
also you can invest at LOAN in poloniex, also you can give Loan to some people trusted at bitcointalk
high profit

Never provide a Loan here High risk of Loss here as well as high profit also
i don't agree, if they can give you a good collateral the risk is reduced almost to zero, so loan with collateral are not risky at all and provide a good return in the short term
the problem is that only few member are providing a good collateral, the majority want to do it without collateral, which result in a scam most of the times
Well, yeah... if they had the collateral, why would they need the loan? It's very rare for someone to need money and have the amount available but not want to use it. Usually this in itself is a sign of a scam.
it's simple such as you want to buy smartphone and you not have money, you can sell your hero member but you feel shame to sell it
then you choose to take LOAN for 1-2 week after you have money you return to pay it
My advice don't accept member who want to get loan without collateral that high risk