Arbitrage is the simplest profit model in financial markets, almost anyone who can do math would figure out where it is most cost-effective to send their money.
When the interest rates for US Dollar or Euro are low, I borrow on a large scale, then look for which country's bank offers high interest rates, and I lend money to them.
Because when you deposit money in a bank, it is actually like lending money to the bank!
Seemingly simple, but in fact, only real big capital can ensure profitability.
Because there are very few places that can handle large amounts of capital right now...
The island country is one, but to combat the harvesting by the US Dollar tide of Daddy United States, they have been implementing negative interest rates for many years.
East is another one, but they have implemented strict capital control policies, with strict controls on both the inflow and outflow of funds.
