Damages for the conversion of stocks, bonds, or other like property of fluctuating value shall be limited to the difference between the proceeds of the conversion, or that portion thereof duly paid or credited to the owner, and such higher value as the property may have reached within a reasonable time after he had notice of the conversion. Where the facts are not in dispute, such period shall be fixed by the court as a matter of law.
42 Pa.C.S. § 8335