As GDX invests in actual companies and firms, it is different from some gold funds Ive recently spotlighted and I can pass on information about the top holdings in the fund. Top 10 holdings for GDX make up slightly more than 50 of total assets, and include a lot of familiar names if you are familiar with mining companies. Barrick Gold Corp. (ABX) is the largest holding, with 6.78 of assets. It is closely followed by Newmont Mining Corp. (NEM), with 6.62 of assets, and Goldcorp, Inc. (GG), at 6.27 of assets.