(a) If you are engaged in a trade or business, you must, in determining your net earnings from self-employment, exclude any gain or loss—

(1) That is considered a gain or loss from the sale or exchange of a capital asset;

(2) From the cutting of timber or from the disposal of timber or coal, even if held primarily for sale to customers, if section 631 of the Code applies to the gain or loss;

(3) From the disposal of iron ore mined in the United States, even if held primarily for sale to customers, if section 631 of the Code applies to the gain or loss; and

(4) From the sale, exchange, involuntary conversion, or other disposition of property that is not—

(i) Stock in trade or other property of a kind which would properly be included in inventory if on hand at the close of the taxable year; or

(ii) Property held primarily for sale to customers in the ordinary course of a trade or business;

(b) For purposes of paragraph (a)(4) of this section, it is immaterial whether a gain or loss is treated as a capital gain or as an ordinary gain or loss for purposes other than determining earnings from self-employment.

(c) For purposes of paragraph (a)(4) of this section—

(1) The term involuntary conversion means a compulsory or unintended change of property into other property or money as a result of such things as destruction, theft or seizure; and

(2) The term other disposition includes destruction or loss by fire, theft, storm, shipwreck, or other casualty, even though there is no change of the property into other property or money.