Because oil prices are set by a cartel called OPEC and various multi-billion dollar corporations who are friends with the presidential candidates. It also puts people in a happier mood wherein they are more inclined to travel, and is usually around holiday times or election seasons.

This is a trend we've seen before; dip 25 or 30 cents before shooting back up 75 cents. This is just a much bigger dip to make people all that much happier. Don't worry, it WILL shoot back up.