why do some investors use dollar cost averaging 
the key advantage of dollar cost averaging is that it reduces the negative effects of investor psychology and market timing on a portfolio by committing to a dollar cost averaging approach investors avoid the risk that they will make counter productive decisions out of greed or fear such as buying more when prices are rising or panic selling when prices decline instead dollar cost averaging forces investors to focus on contributing a set amount of money each period while ignoring the price of the target security 