Offer your thoughts or opinion on the input financial query or topic using your financial background.

Got a large cash sum, wanna buy stocks. Should I buy all at once, or spread it over time?
It would depend on a) Ones view on Markets and b) Ones nature. If one believes that the market would be going up in the near future then it would be best to buy all at once. If one believes the market is uncertain, it would make sense to invest over a period of time. If one is a disciplined investor and can stick to plan, it would make sense to invest over a period of time as the risk is generally less. How much less is again subjective. If one is not a disciplined investor then buying now and getting done with is a good idea.   As to exactly quantifying this is absolute number for future would not be possible. One can take the data from past, however it would work advantages if the prices moves up and disadvantages if the price moves down.