Dollar cost averaging - Should I still do it if I have a large pile of cash now?

Dollar cost averaging performs better in an oscillating market. Lump sum investing performs better in an up trending market. So what's the market going to do going forward? No one knows so it's impossible to know which method of entry you should employ.

Then there's the issue of your internal conflict. You feel that you should be invested but you are of the opinion that you're late to the game and that "given that currently the stock market is at a high and there is a lot of economic uncertainty on the horizon, putting everything in the stock/bond market at once now seems like a risky move."

What to do, what to do? Screw the "principle of dollar cost averaging". What do you feel comfortable with? What's your risk tolerance? Are you chasing all out equity exposure to match the market? Or a blended approach of growth and income? Or perhaps a steady level of income? What balance is acceptable to you?

I'm no longer familiar with Vanguard products and I'm not attempting to give you investment advice - just some additional ideas. And no, I'm not in the business - just a retail investor/trader.

You could park some of the money in a preferred stock ETF. They're currently paying about 5.5% per year, exceeding your CD rates. They're lower risk than common stocks but they are subject to interest rate risk (long term not Fed fund rates).

I'm going to go out on a limb and mention something outside the box. There are some interesting structured index annuities that offer varying levels of downside protection with an upside cap. Five year annuities with one year segments. At AXA, you can get 10% of downside protection with a 7.6% cap on the S&P 500. So if you put $100k in the S&P model, you don't lose a penny of the first $10k of drop and you make whatever the index is up, up to $7.6k One year from now, your principal resets to the value of the index.

Brighthouse (formerly part of Metlife) has a variation of this where it's six years with a similar one year segment cap (say it's the same at 7.6% cap) but it has a Step Up feature where if the index is up ONE penny at the end of the year, you get the 7.6% while still protected against the first 10% of drop.

Apart from the Step Up feature, these annuities aren't really good deals because you can simulate the product with options and do far better. At today's prices, you can do the January 2019 SPY combo (10 months out) and receive 20.6% of downside protection (double what the annuity provides) with a similar 7.8% cap. If you want more profit potential, you can give up some of the protection so another choice could be 19.4% protection out of a 20% drop with a cap of 8.4%. Or if risk is less of a concern, you could set up a 11% downside protection with a 11% cap. And so on...

The point of these ideas? You can double the CD rate with some preferred stock ETF exposure. You can invest some of the money in simulated structured annuity positions with 20% downside risk covered (dealing with your over valued market concern) yet have some upside potential if the market is good. IOW, if the market tanks, this component will be owned at 80% of the current value of the SPY (or 90% if you opt for the higher risk, higher cap) which is essentially DCA. Or you can go all out and plunk everything in the market right now, accepting whatever return it gives you, good or bad, going forward.

There's no one size fits all answer so I'd also suggest that you meet with financial advisers to move you up the financial food chain. You can get free consultations at Edward Jones, JP Morgan Chase Bank, TD Ameritrade, et al. Let them work up a plan for you and provide additional ideas. You don't have to give them a penny unless you find something that really intrigues you. And if you're really clever, you can duplicate it at Vanguard. The more information you have, the more able you'll be able to craft an approach that fits your needs and risk tolerance.

As I see it, it comes down to a trade-off between the highest expected value (invest everything in shares asap) which is also associated with the highest uncertainty/volatility/potential downside risk. Even the potential for value loss can cause anxiety, so playing safe has some value all by itself.

In this situation, the following is the strategy I would feel most comfortable with. I haven't seen this answer anywhere else, and I'm not sure what the investment community would think of it (feedback welcome).

I would do something like "exponential dollar cost averaging". I would invest exponentially decreasing amounts each year until I reach my long term allocation target. For example, if I'm aiming to reach an allocation with 80% of my wealth in shares, I would put in 40% the first year, 20% the second year, 10% the third year... Eventually that would reach 80%. (I might round up the last few payments so that I didn't have to wait infinite years to reach the goal.) I would also spread the initial large investments over the course of the year, assuming that transaction costs/fees aren't too high.

It would be important to maintain diversification over the whole course of the investment, so I would start with an investment in a highly diversified ETF. (e.g. Vanguard, as OP suggests.)