California Code, Probate Code - PROB § 13545

(a) After the death of a spouse, the surviving spouse, or the personal representative, guardian of the estate, or conservator of the estate of the surviving spouse has full power to sell, assign, pledge, or otherwise deal with and dispose of community or quasi-community property securities registered in the name of the surviving spouse alone, and the right, title, and interest of any purchaser, assignee, encumbrancer, or other transferee shall be free of the rights of the estate of the deceased spouse or of devisees or creditors of the deceased spouse to the same extent as if the deceased spouse had not died.

(b) Nothing in this section affects or limits the liability of a surviving spouse under Sections 13550 to 13553, inclusive, and Chapter 3.5 (commencing with Section 13560).