First off, understand that any answer here is going to be incomplete -- you haven't provided nearly enough information for a full answer, and I strongly recommend working with a financial planner who has a fiduciary relationship with you (i.e. who must put your interest first, not necessarily selling you products first).
That said, the issues revolve around your *goals* and *needs* for that money. Are you planning on living off that money? Will it provide supplemental income (above and beyond your needs, which are met by other resources)? Do you have other resources (Social Security, pension, etc.)?
A few things to note:
1) Historically, a 50/50 stock/bond portfolio has returned between 5.25 and 5.75% above inflation *over long periods of time* (Vanguard did a great study on this targeting periods of economic expansion and downturns). I am not recommending that portfolio - only presenting it to give you an idea regarding reasonable expectations.
2) Risk and reward go hand-in-hand. It's not a perfectly direct relationship, but it's not possible to get huge returns without taking huge risks - anything which can make you stupendously rich can also wipe out your investment. Don't believe anyone who suggests otherwise.
3) Longevity is a major issue if you're considering pulling cash-flows out of the portfolio -- if you start with, say, a draw of 4% of the initial value of the portfolio and increase that draw with inflation as you go, historically, such a plan has "worked" over long periods of time very well. However, there were also historical times where it failed -- mainly in time periods where markets went down early on in the life of the process. If you want to guarantee that the portfolio will last until you die, the only ways to do that are either extremely small draws -- or partial annuitization.
So, again, it comes down to the same question -- what's the money for?
If you already know how you want it invested (i.e. you've already selected a suitable target allocation and have considered time horizons, risk tolerance, draw-down plans, etc.), then your question may just be "Do I put it all in at once or do I ease into it?" The answer to that is personal. On the average, over long periods, again, the sooner you put all of it to work, the better. However, that also means immediately embracing the full volatility of your target portfolio. If you aren't comfortable with that -- or if you think markets are high right now -- there's no reason not to ease in through putting, say, 25% to work at a time over the course of, say, a year. But don't take too long -- too much cash for too long is effectively a guarantee of a loss of value (since cash is earning less than inflation).
| 05.24.16 @ 19:32