I was thinking that with dollar cost averaging buy, we actually can do the same thing when we sell: just sell $100 per day, just like we were buying $100 per day.
However, won't that cause a total chaos when reporting tax? It could be, the selling of this 0.7854234 shares is associated with the share bought at $163.82 for 0.3313123 shares, and then $168.23 for 0.27134758 shares... oh but wait, I already supposedly sold those shares at a higher cost one month ago, so which ones did I sell for these 0.7854234 shares... I mean, it could almost drive a person crazy just doing 0.7854234 shares, not to mention doing 365 of them for the year. (or 250 of them for market open). And imagine if you have to do it for 2 or 3 stocks, so it is 500 or 750 of this. By the time you are done, the year may be already over.
So what can be a feasible solution?