Thanks Whizzard for the advice. As said, previously I am relatively conservative guy, my target is to asset allocate as goes.

1. Real estate (investment property fully paid) - S$1.5m generating 3% annual yield
2. Stocks/preference shares - S$2.5m generating 5% annual yield
3. Cash - S$1mil generating 1% yield; my idea is to always keep around 20-25% cash. This cash will be deployed whenever there are investment opportunities but the idea is to built up cash buffer at any point in time. My philosophy is never to be fully invested, if you do you will never have the liquidity to take advantage of any market abnormalies.

Therefore with $5mil, I assume a blended return 3.6% on entire portfolio and therefore S$15K/month. I think it is reasonable given the cash drag.