In March 2025, the Australian Financial Review published a feature on RSU wealth management. I was quoted on the number I’ve used with clients for years:

“People say you don’t want to have more than 5 or 10 per cent of your stock in any one investment.

But with a lot of these people having been given millions of dollars worth of shares, my long-term comfort level is about one-third.”

— Mike Sikar, Delta Financial Group, Australian Financial Review

The 33% Rule is not a number I pulled from a textbook.

It’s the threshold I’ve arrived at after working with 250+ tech executives across 15 years of practice. It accounts for the fact that these clients are already exposed to their employer through their salary and career — so the equity position needs to reflect that existing concentration, not ignore it.

When RSUs vest, the question isn’t hold or sell. It’s: what percentage should I retain, and what happens to the rest?

👉 Retain up to 33% of vested shares if you have genuine conviction in the company’s long-term trajectory

👉 Sell the remaining 67% immediately and redirect into a diversified portfolio

👉 Never let a single stock exceed 33% of your total net worth

If in doubt, I advise clients to practise what I call “regret minimisation”.

“Don’t hold all your eggs in one basket, sell some shares, pay some taxes, and maybe even pay down your mortgage.

Simple stuff, but no one’s ever felt bad about paying down their mortgage.”

— Mike Sikar, Delta Financial Group

RSUs are compensation. Not a retirement strategy on their own.

When handled with The 33% Rule, they become one.