Easy "A Lot Of Cheddar" achievement

After completing the story, you should have approximately $20 million available. Open the internet browser, go to the "Money And Services" tab, and open the LCN stock exchange website. Then, invest all your money in stocks, and immediately sell them. You will not lose any money if you sell the stocks quick enough. Keep repeating this until you get the "A Lot Of Cheddar" achievement. Note: You can also do this earlier in the game with less money, but it will take longer. To view how much money you have already spent, go to "Cash" in the statistics of the pause menu.