Section 38National Internal Revenue Code of 1997 (Republic Act No. 8424), Sec. 38

Losses from Wash Sales of Stock or Securities. -

(A) In the case of any loss claimed to have been sustained from any sale or other disposition of shares of stock or securities where it appears that within a period beginning thirty (30) days before the date of such sale or disposition and ending thirty (30) days after such date, the taxpayer has acquired (by purchase or by exchange upon which the entire amount of gain or loss was recognized by law), or has entered into a contact or option so to acquire, substantially identical stock or securities, then no deduction for the loss shall be allowed under Section 34 unless the claim is made by a dealer in stock or securities and with respect to a transaction made in the ordinary course of the business of such dealer.

(B) If the amount of stock or securities acquired (or covered by the contract or option to acquire) is less than the amount of stock or securities sold or otherwise disposed of, then the particular shares of stock or securities, the loss form the sale or other disposition of which is not deductible, shall be determined under rules and regulations prescribed by the Secretary of Finance, upon recommendation of the Commissioner.

(C) If the amount of stock or securities acquired (or covered by the contract or option to acquire which) resulted in the non-deductibility of the loss, shall be determined under rules and regulations prescribed by the Secretary of Finance, upon recommendation of the Commissioner.