It depends on the potential of a coin; if the coin is good, buying it early, like in a presale, will give you a good profit. A presale offers a bonus percentage in every stage, so if a coin has good potential and community support, strategic accumulation in its presale is better than buying it after the listing.
Some investors prefer buying a coin on their favorite exchange, which is why they prefer to buy it if there is an announcement of listing on their preferred exchange.