The Black-Scholes-Merton price of an out-of-the-money call option with an exercise price of $$\$ 40$$ is $$\$ 4$$. A trader who has written the option plans to use a stop-loss strategy. The trader's plan is to buy at $$\$ 40.10$$ and to sell at $$\$ 39.90$$. Estimate the expected number of times the stock will be bought or sold.