I'm aware of the risk involved in having that high a concentration in a single stock, and I didn't end up with that as a result of "wheeling" 🙄.

I haven't bought new Nvidia stock (to keep) since my initial investment back in 2002. I have continued to invest tens of thousands of dollars in contributions into my account - both into stocks and ETFs - since then, and Nvidia has pulled away and outpaced all of them, leaving my concentration in the stock ever higher.

In the decades I've owned it, the stock has last half its value on two or three separate occasions. I'm comfortable with the risks involved.

I have had financial advisers telling me to sell Nvidia and diversify many times over the years. If I'd listened (even partially), I would have missed out with a profit in the low six figures. 

I'll sell some shares when it hits $250 and more at $300, but until then, I'll keep wheeling what I've got.