<prompt> Human: For reference, I am a college student who landed an internship for over the summer. I should make about 10,000 in addition to about 2,000 for coaching a swim team. The 2,000 will be enough to get me through the school year next year, so I am looking to invest the majority of the 10,000 in a very safe mutual fund that has been averaging about 5-6 annual interest just as a way to get my feet wet into finances and as a way to have it grow at a good clip.Here is the mutual fund in case anyone is interested I already know Vanguard is one of the best places to go, as they have some of the lowest upkeep fees in the business.I do not want to put it in an IRA. I have thought about this, and while, long term, it probably would be the best choice for me, I am interested in seeing this money penalty-free at the end of college.So anyway, to explain my question a little more in-depth. With this 10,000 and presumably any other money that I make in remaining summers interning, is my best choice A to invest it all as I make it so paycheck by paycheck? B To hold onto it and make monthly deposits of about 800 into a fund to account for ups and downs of the market? Or C To invest all of it at once at the end of the summer?Thanks!EDIT: The account is the lowest-risk option. With 80 in bonds and 20 in the market I believe primarily SP and a little international.Assistant: You are asking which is better: dollar-cost averaging or lump sum.Research says lump sum is the way to go.Vanguards research article on this subjectHuman: Thats if you have a large lump sum up front. But he is saying he doesnt have the 10K up front, but he will be making 10K over time. In that case using DCA is the better move.To some readers, our research may seem to discount the benefits of dollar-cost averaging often cited in popular financial commentary. Such articles tend to recommend DCA largely on the ground that investing a consistent dollar amount at regular intervals allows investors to diversify the prices they pay for a security, buying more shares when prices are low and fewer when prices are high. This is true, but there is a notable distinction between DCA as commonly discussed and as a subject for the research covered in this paper. Most popular commentary addresses DCA in terms of consistent investments made using current incomei.e., an employee transferring a portion of each paycheck into a retirement account. In that case, investable cash becomes available only in relatively small amounts over time, which makes DCA a prudent way to invest and really the only sound alternative to accumulating that money in cash and then actively trying to time the market at some later point. Our research, in contrast, focuses on the strategies for investing an immediately available large sum of money. Here, the average performance results have favored lump-sum investing. Assistant: Well yes, I would invest it pay-check to pay-check. But essentially, that is a series of lump-sum investments as opposed to making the 10,000 then paying 866month for a year.At least as the way I see it.  <response>: Waiting until you have 10k and then investing it all at once would be combining the downsides of dollar cost averaging losing out on the statistically likely gains from investing earlier with the downsides of lump sum investing the risk of a sudden downturn shortly after investing. Worst of both worlds.So yep, doing it paycheck by paycheck is definitely the best course of action for you. 