<prompt> Human: Im selling all shares of a Vanguard mutual fund that I gained access to through an UTMA account. Im being asked to chose a method of cost basis before I can sellexchange the shares. It sounds like Vanguard automatically calculates cost basis information if you use average cost, but choosing another method requires information on my part for shares bought prior to January 1, 2012.I dont totally understand the distinctions between the cost basis methods they offer avg cost, FIFO, specific ID, but does it matter which I choose given I will be selling all shares? All I want to do is minimize the amount of capital gains taxes I will be potentially on the hook for.  <response>: It doesnt matter if you are selling all shares. 