The references to gain and loss in sections 2 to 4 are to be read in accordance with this section.
“Gain” and “loss”—
extend only to gain or loss in money or other property;
include any such gain or loss whether temporary or permanent;
and “property” means any property whether real or personal (including things in action and other intangible property).
“Gain” includes a gain by keeping what one has, as well as a gain by getting what one does not have.
“Loss” includes a loss by not getting what one might get, as well as a loss by parting with what one has.