I've been using both TD Ameritrade and Robinhood for a while. I just learned that on TD Ameritrade, you can use the specific-lot-matching method when you sell your shares.
It's in My Account -> Cost Basis -> Unsettled Close Positions -> Click on the green arrow next to your trade after you sell, and you can select which lot to redeem your trade against. The clearing house confirms the trade in seconds, but by federal law the money takes two days to actually transfer. You have until then to select the lot using this method. So says TD Ameritrade.
Pretty cool. So cool in fact that I'm considering moving a bunch of stocks from Robinhood to TD Ameritrade. But my question is, after I make this transfer, can I sell shares on TD Ameritrade that I originally purchased on Robinhood and still use this technique? I called TD Ameritrade and they couldn't answer that question. Any help is appreciated.