What Becky said about lighting is very important in all graphics. In this case, maybe you could even use the lighting not only to enhance the stock, but the background. The background is a little bland, and while the stock stands out more because of it, it feels like there is just too much empty space. The right side of the signature looks nice, it's mostly the left side that I feel has this "empty space" problem. Overall, it looks pretty and it's a great start to what could be an even cooler graphic!

It reminds me of a snowy day and the random dots are oh-so pretty an effect. ^^ I'd like to see more from you~