Dollar cost averaging is a technique designed to reduce market risk through the systematic purchase of an investment at predetermined intervals and set amounts. Instead of investing in a lump sum, the investor buys smaller amounts over a longer period of time. This spreads the cost basis out over several years, providing insulation against changes in market price.

It is not only better investment wise but easier to save money.  Investopedia has a great video on dollar cost averaging.

Watch it here.