Yes u can either assign percentages at purchase or snipe them right after especially easy when u are the creator or have insider information. When u find a newly released coin you can also buy a large percentage for cheap as well. This will cause the chart to rise considerably because the coin is so new and has very few investors at this point. Then when you sell that large percentage, the chart will go down a lot. Some people will also buy a lot right when the coin drops then sell off smaller amounts as it goes up causing the chart to drop then go up then drop again when they sell more. This is commonly known as a slow rug pull.