what happened is that you exercised the options. income was realized and added to your W-2. thus some of the stock was sold to cover the taxes. generally, if sold the same day as the exercise your sales price and tax basis should be equal or almost equal so there is little or no gain or loss. so I'm thinking g that the 1099-B is not reflecting your proper tax basis. I would think your basis in the stock sold would be the income added to your w-2 divided by the number of shares received times the number of shares sold.
