The discussion of risk and returns suggests that technical analysis may be very useful for banks and large financial firms that can borrow and lend freely at the overnight interbank interest rate and buy and sell in the wholesale market for foreign exchange, where transactions sizes are in the millions of dollars.
Technical trading is much less useful for individuals, who would face much higher transactions costs and must consider the opportunity cost of the time necessary to become an expert on foreign exchange speculating and to keep up with the market on a daily basis. How large would transactions costs have to be to eliminate the excess return to the technical rules? If we assume a 6 percent annual excess return to the rule and 230 trades (10 trades a year), round-trip transactions costs would have to be greater than 0.6 percent to produce zero excess returns.
