I work full time in the internet marketing space arbitraging clicks between exchanges in an essence I don't spend any money because it's all on the suppliers credit and if any clicks result in fraud I can chargeback the supplier for the clicks. This is a rare opportunity to find pure arbitrage where you have no price risk an risk none of your actual capital because I'm also buy and selling simultaneously.

If your unfamiliar with the concept read here http://people.stern.nyu.edu/adamodar/pdfiles/invph...

A lot of opportunity in financial markets also exists even not trading between exchanges chasing price variances. 

I'm newly getting into real estate. Are their any concepts out their for arbitraging anything? In stored commodities you can make money off a simple difference in commodity pricing due to a higher or lower cost to hold the good on inventory. 

Maybe this is possible holding a loan at say 4% interest and charging rent of what would be 8% interest without actually having to put any money up for a loan based on collateral for a property? 

Maybe even going as far as listing things in different countries for the same price and looking for currency differences in pricing models? Are their any exchanges where you can trade real estate derivatives to capture price variations outside the stock market? 

Maybe brokering mortgages could work if your buying and selling simultaneously. 

Lets hear your creative arbitrage ideas for real estate.