For what it's worth, stocks went up in Q4 from 2010-2012.

Past performance is no indication of future gains and all that, but the economy's ups and downs have been relatively consistent during this slow recovery (i.e., Q2 has been down or flat).

All at once. I think the traditional thought is 1/3, 1/3, 1/3, but the difference with market fluctuations in relation to $100k is minuscule over time. The market could go up or down, but not enough to make much of a difference. It would not be enough to worry about.

Just do it and forget about it.

However, if it were me , I'd buy dividend yielding stocks.

You should invest it all at once. You're not smarter than the market, so you should start earning returns as soon as possible. If you're very concerned about a market downturn, it can affect your choice of assets, but should not affect when you invest.

If you're doing three fund you might want to consider putting a portion of your bond holdings into I bonds rather than a fund. It'll be more tax efficient and won't lose money in the near term. Also, if you don't need the money at any point in the near future, definitely have a gander at this:

http://www.bogleheads.org/wiki/Principles_of_tax-efficient_fund_placement

As far as lump sum investing goes, the rule of the day is "Know thyself". On average, putting it all in at once has provided better returns. If you can look at your investments dispassionately (ie, "I own X number of shares" as opposed to "I have X number of dollars") the lump sum approach is not necessary. If the market dropping 10-20% will keep you up at night with regret, then go ahead and dole it out at reasoned intervals.

Do you have an emergency fund?

You can find discussion of this over at the bogleheads forum. Basically from a theoretical perspective you should probably invest it all at once, but it's okay to spread it out if it makes you feel better.

Consider whether it would bother you if you invested it all and the market went down 10% over the next six months (or if you delayed and the market went up 10%).

First, thanks to those on this board for helpful advice on money issues. I’m learning a lot lately!

I have $100K to invest from recent sale of house. Retirement funds maxed. Now looking into the 3-fund approach. I’m not doing anything too risky—just index funds. My question is do I invest all the money at once? Or should I invest some amount each month so I can vary the price points (taking advantage of buying more shares if lower for example)? Similar to how I do my IRA contribution monthly? But maybe the prices don’t vary enough to make a monthly approach in this situation worth it? Appreciate thoughts!