The (Rockland, N.Y.) Journal News:Despite frequent predictions that MasterCard Inc.'s stock will slow, it has spent most of this year speeding to new heights. Shares of the Purchase-based company have gone from $39 to $169.71 since MasterCard held its initial public offering in late May. MasterCard's $2.4 billion IPO has proved so successful that Visa International Inc., its biggest rival, has announced plans for its own IPO next year.