During pre-market/post market time, the Last Price should show the last price during the market open time. There are already separate columns for pre-market price.

For the Day Chart column, the graphic for the mini-chart should not include Pre-market/post-market data in the mini chart. There should be an option to either include the pre-market/post-market data in the mini-chart or create a separate column for a Day Chart that includes 'extended hours'.