Why is statistical arbitrage so-called? Arbitrage originally meant a pair of offsetting positions that lock in a sure profit. An example might be selling gold in London at $300 an ounce while at the same time buying it at $290 in New York for a $10 gain. If the total cost to finance the deal and to insure and deliver the New York gold to London were $5, it would leave a $5 sure profit. That’s an arbitrage in its original usage.
