# Estimate probability distribution of profit on investment [closed]

How can I estimate the probability distribution of the profit on investment if I put my money in, say, S&P 500?

Beyond knowing my expected return, I want to know such things as: What are the chances my investment will be below 50% at the end of 5 years? What is the median expected value (the value at which I can be 50% sure my investment will be above that)?

## closed as too broad by Grade 'Eh' Bacon, Michael, Nosrac, mhoran_psprep, Nathan LMay 26 '17 at 21:37

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• Are you asking for someone to provide you with research? You would estimate this by gathering the data and working up the statistics. – quid May 25 '17 at 23:08
• @quid: I would have thought this is a very common thing and was hoping that someone could either link me to the probability distribution or explain to my why I'm wrong. – Zaz May 25 '17 at 23:29
• The Personal Capital website does this for you and takes many factors into account. – gaefan May 26 '17 at 13:07
• While you may not be aware of this, you are basically asking how to value your asset, and also forecast various possible events. When a question asks something like "I want to know such things as...", it is an indication that it is too broad to be answered here. If you have a specific question that is answerable, you may want to re-ask, but even the most concrete: "What is the probability that the S&P500 will be down 50% in 5 years?" is going to be very technical & opinionated, and already veering into the arena of "should I invest in the S&P500?" – Grade 'Eh' Bacon May 26 '17 at 15:33
• @Grade'Eh'Bacon: I think that "what is the probability of being down X% in Y years" is likely too broad. But I think "how do I calculate the probability of being down X% in Y years" is on topic, and it seems to me like that is what this question is asking (although it could be asked better). I think it's legitimate to ask how to approach the question of estimating future returns, although the answer may be complicated. – BrenBarn May 26 '17 at 18:31