Seeking Advise on utilizing my 4M USD cash?

I am 49 years old and have had a reasonably successful career with multiple start ups and currently working at a very small security startup in Stealth mode. I have been able to accumulate 4 million USD in cash now and want to make use of it the best way. Here is how I am using some of it, but need help on the remaining:

I have allocated 1 million USD for stock investing as that has been my passion since last 20 years and also worked well for me:

1) 300K in Motley Fool 100 Index - https://www.fool100.com/

2) 300K in StockBuzzNow portfolio mirroring - https://www.stockbuzznow.com/

3) 200K in Fidelity ZERO Large Cap Index

4) 200K in iShares Core S&P 500 ETF (IVV)

I want to continue keeping about 1 million in cash for security. Is that a bad idea?

The remaining 2 million is where I am seeking help. Should I consider investing in real estate? If so, any good suggestions as I have very little experience with it (only bought my own home). Or should I put more in ETFs or individual stocks? I am also thinking to put some money in Schwab S&P 500 Index Fund (SWPPX).

Thank you in advance.

#personalfinance #investments