No common trust fund established under s. 223.055 or 223.056 shall be subject to taxation as a corporation, association, partnership, limited liability company or individual, but it shall be a fiduciary within subch. II of ch. 71. All income of such trust and all capital gains and losses shall be income received or loss realized to the fiduciary account holding a participation in such common trust fund in accordance with its participation.
Wis. Stat. § 223.057