A Long Butterfly

Buy one call option with an exercise price of $50 for a premium of $10.

Sell two call options with an exercise price of $60 for a premium of $10 (each).

Buy one call option with an exercise price of $70 for a premium of $10.

The largest loss from this strategy would be ________.

To have a positive profit, the spot rate on the expiration date should range from ________ to ________.