Lets say you have 1000 Steem and Steem is worth a dollar so your value would be 1000$ right? But the price is going up and down, but this is not reflected imediately, guess its 3,5 days behind.... So if the Steemprice where down, 3,5 days ago, thats what you are seeing now.... It should look different 3,5 days from now :) because the price is up again. Got it?