Hi Nokia,
Smart question! 
I checked into this and since a negative point balance would typically be the result of a return – meaning you returned a purchase and therefore, the Reward Zone points earned on that purchase were then deducted back out of your point total, it would carry over through the annualization.
Sorry this isn’t the answer you were probably hoping for but thanks again for asking!
 | Sarah | Community Connector | Best Buy® Corporate |  |