<prompt> Human: My son just turned one and Im opening a 529 for him. I have two options of enrollment:1. Guaranteed savings plan- basically you pick 15 tuition levels and save the cost of a current semester of a school and it keeps pace with the rising tuition. So if my level of schooling I choose currently costs 5,000 per semester, if I save 5,000 it will cover the cost of that level of school even if cost goes up. 2. Investment plan- I choose my investments from 15 vanguard funds. Per their report, the highest 12 yr return in their options is their overall stock index at 8.52 The second highest is an aggressive growth portfolio, again 12 years, at 7.2I would love to hear thoughts on these two option.  <response>: It probably depends if you think they will attend one of the schools covered by the tuition plan, and how much you think tuition will increase relative to the stock market.I actually did a prepaid tuition plan for two kids, but on a shorter timetable, and it was a no-brainer because my state actually dropped tuition prices during a time of flush budgets...that obviously wasnt going to last, and it didnt. I did a lot better than I would have in the market for the kid that used his four years tuition; for the one who dropped out after three semesters, it was not as good as I would have eventually done in the market had I held the funds equally as long after he dropped out. All things considered, option number 2 is probably better for you, but its not a given. 