Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Over how much time should I dollar-cost-average my bonus from cash into mutual funds?
The OP invests a large amount of money each year (30-40k), and has significant amount already invested. Some in the United States that face this situation may want to look at using the bonus to fund two years worth of IRA or Roth IRA.  During the period between January 1st and tax day they can put money into a IRA or Roth IRA for the previous year, and for the current year. The two deposits might have to be made separately, because the tax year for each deposit must be specified. If the individual is married, they can also fund their spouses IRA or Roth IRA.  If this bonus is this large every year, the double deposit can only be done the first time, but if the windfall was unexpected getting the previous years deposit done before tax day could be useful.  The deposits for the current year could still be spread out over the next 12 months. EDIT: Having thought about the issue a little more I have realized there are other timing issues that need to be considered.