(a) Basis for determining gain. In the case of property acquired before March 1, 1913, the basis as of March 1, 1913, for determining gain is the cost or other basis, adjusted as provided in section 1016 and other applicable provisions of chapter 1 of the Code, or its fair market value as of March 1, 1913, whichever is greater.

(b) Basis for determining loss. In the case of property acquired before March 1, 1913, the basis as of March 1, 1913, for determining loss is the basis determined in accordance with part II (section 1011 and following), subchapter O, chapter 1 of the Code, or other applicable provisions of chapter 1 of the Code, without reference to the fair market value as of March 1, 1913.

(c) Example. The application of paragraphs (a) and (b) of this section may be illustrated by the following example:

Example:(i) On March 1, 1908, a taxpayer purchased for $100,000, property having a useful life of 50 years. Assuming that there were no capital improvements to the property, the depreciation sustained on the property before March 1, 1913, was $10,000 (5 years @ $2,000), so that the original cost adjusted, as of March 1, 1913, for depreciation sustained prior to that date is $90,000. On that date the property had a fair market value of $94,500 with a remaining life of 45 years.

(ii) For the purpose of determining gain from the sale or other disposition of the property on March 1, 1954, the basis of the property is the fair market value of $94,500 as of March 1, 1913, adjusted for depreciation allowed or allowable after February 28, 1913, computed on $94,500. Thus, the substituted basis, $94,500, is reduced by the depreciation adjustment from March 1, 1913, to February 28, 1954, in the aggregate of $86,100 (41 years @ $2,100), leaving an adjusted basis for determining gain of $8,400 ($94,500 less $86,100).

(iii) For the purpose of determining loss from the sale or other disposition of such property on March 1, 1954, the basis of the property is its cost, adjusted for depreciation sustained before March 1, 1913, computed on cost, and the amount of depreciation allowed or allowable after February 28, 1913, computed on the fair market value of $94,500 as of March 1, 1913. In this example, the amount of depreciation sustained before March 1, 1913, is $10,000 and the amount of depreciation determined for the period after February 28, 1913, is $86,100. Therefore, the aggregate amount of depreciation for which the cost ($100,000) should be adjusted is $96,100 ($10,000 plus $86,100), and the adjusted basis for determining loss on March 1, 1954, is $3,900 ($100,000 less $96,100).

(d) Fair market value. The determination of the fair market value of property on March 1, 1913, is generally a question of fact and shall be established by competent evidence. In determining the fair market value of stock or other securities, due regard shall be given to the fair market value of the corporate assets as of such date, and other pertinent factors. In the case of property traded in on public exchanges, actual sales on or near the basic date afford evidence of value. In general, the fair market value of a block or aggregate of a particular kind of property is not to be determined by a forced-sale price, or by an estimate of what a whole block or aggregate would bring if placed upon the market at one and the same time. In such a case the value should be determined by ascertaining as the basis the fair market value of each unit of the property. All relevant facts and elements of value as of the basic date should be considered in each case.