The first thing to consider is the total number of shares you have to work with at a time. When you have more shares to buy or sell, you might get more favorable rates. This is because a broker will notice how committed you are to a sale. The chances for you to make a good deal of money, in this case, may be good.
For the Six Flags example, you might have a number of shares with the stock listed at $66.73. You might be encouraged to sell up to 100 shares at $59.98 each. However, when you sell more than 100 shares, you might get a slightly better price a little closer to the $66.73. The ask price might be too lofty in some cases. The $67.29 x 4000 ask price total results in paying less for the stock if you buy more than 4,000 shares. Even then, that might be extremely difficult to do. You’d have to spend at least $265,000 just to buy 4,000 shares. The total value of each share might move a little closer to the actual listed price when you go over the 4,000 share mark, but you might be spending far too much money on the shares at that juncture.