NEW YORK (AP) â¿¿ Capital Gold Corp., a gold mining company, said Thursday that it will join the Russell 3000 Index of stocks on Friday. Capital Gold said its shares will be added to the index when Russell reconstitutes its U.S. and global stock indexes. Annual reconstitution of Russell's U.S. indexes captures the largest U.S. stocks as of the end of May, ranking them by total market capitalization. Membership in the Russell 3000, which remains in place for one year, means automatic inclusion in the large-cap Russell 1000 Index or small-cap Russell 2000 Index. Stocks often rise after they are added to major indexes as they are bought by managers of investment funds that mirror the indexes. Capital Gold shares rose 15 cents to end at $4.03 in regular trading Thursday.