A speculator opens a position in a futures contract in a 3-month banker's acceptance. At the time that the position is opened, the quoted price for a contract is 98.00 (one contract is for 1,000,000 banker's acceptance). The margin required to open the account is $500. One week later the quoted price on the futures contract is 98.10. The speculator closes the account. Find the speculator's one-week rate of return on the initial investment of 500.