It's December in the first full year that I've been FIRE and I would like to make my first mutual fund sale in my Vanguard account. While I have many years of experience buying, I haven't ever sold before. I'm using the Affordable Care Act for insurance coverage, so I'm hoping to come up pretty close to the number I estimated for my 2020 income as part of my Heathcare.gov application so that I don't end up owing extra money for my health coverage when I file my taxes. I've gone through my account and made a pretty good guess for dividends and interest, so all that is left to account for is what my cost basis will be for whatever funds I sell.
When I log into Vanguard, I can click on an option to see my cost basis, however it's not showing any data for VTSAX. Is there a way for me to see what my cost basis will be before I sell? [I just upgraded my account to brokerage yesterday, could this be why I can't see my cost basis?]
Thanks for any insights!