Dollar cost averaging helps to spread out your risk since you won't be investing a large lump sum only to find out that the price drops a lot later. Additionally it's good if you can't spare that much cash each time, although it's true that the transaction fees might add up over time. Lastly for those new to investing or for those who are especially risk-averse, DCA helps you to overcome the mental inertia needed to invest (either from procrastination or fearing to invest due to uncertainty).