likely still purchased the stock. After market trades are not made on the exchange, but are made using a system (ECN) that matches willing buyers and sellers without using the traditional exchange. You will often see the bid/ask spread vary wildly in after-hours trading and you have to pay what others are willing to sell at (the asking price). Because there are a lot less traders at this time (less volume), the price becomes far more volatile

So, if the market price at close was $4.96/share, if there is a lot of demand in the after-hours market the sellers may increase their ask and you may have paid something like $8/share. This doesn't necessarily mean it will open tomorrow with an increased price. When the market opens and you have all of the volume of buys/sells, the price will adjust appropriately. The risks of after-hours trading can be significant (both positive and negative).