We are still about 6 years out on retiring (based on DD college schedule). I have about 900k in cash that I have been waiting to invest. I think the market will correct I'm both equities and housing in the next 18 months.
Would you sit and wait for buying opportunities, get some CDs, or invest in hookers and blow?
You have already gotten conflicting advice, I might as well keep the streak going!
Six years is a decent length time horizon, wish it was a bit longer. Obviously you are trying to pounce on a correction and deploy your cash to buy bargains. The problem is you never know when that time might be. You need to do something with your cash. For example you could have been making $2,000 - $2,500 a month with it sitting in a couple of fairly safe bond funds.
You don't sound like an index fund investor to me.
With that mindset I would invest about $200K in some aggressive US large cap mutual funds that have a history of beating the index funds. These should be no load funds with a relatively low (for their class) expense ratio.
About $50K would go into the same thing in a US mid-cap fund. Another $50K would go into a similar US small cap fund.
I'd put $150K in large-cap foreign fund.
If you want to play around with individual stocks I'd limit the amount of money in this pool to $50K or less.
The rest of the money I would put in a US total bond fund.
This strategy will give you approximately a 60/40 equity/bond mix.
When the correction comes I would sell off a good chunk of the bond fund and buy into bargain equities, either individual stocks or mutual funds.
If you are OK with index funds I would allocate the $500K in equity index funds and the other $400K in index bond funds. When the correction comes sell from the bond funds and buy equities.
When the dust clears, reallocate your assets to an appropriate risk level.