After thinking on it. Imsully2 is correct. What I actually did was copy my Excel spreadsheet of what I have and then pasted it into the tradelist area without entering the cards into my inventory first. That way it auto adds my trade list quantities to my inventory quantity. I figured it out about halfway through manually entering the cards into my inventory then manually changing the quantity in my tradelist section. Of course...this is only really helpfull if you want all your cards in your tradeslist as well.
You could goto the print option of your inventory...copy the list and then delete your inventory as Imsully2 stated and then paste your list back into the tradeslist section and it will automatically fill in your inventory quantities to match your tradelist. Or wait for 2.0
All I know is I just love this site as it is a lot easier then having to carry all my cards wherever I go if people want to trade. This way they can check out my inventory without having to man-handle every card. Since I keep my stock alphabetized by color and type...it makes finding what they want that much easier.
Thank you to the developers for a awesome tool.