Subject: Re: OT: S&P versus T-Bills?
Do you have the data for this? ie: How many sub-periods in the past 10 years has QQQE out performed QQQ?

It's probably not worth bothering. The last ten years have been basically one long gigacap bull market.

One reversal in 2022. Tinier hiccups around end 2018 and end 2020. But anyone not overweight the super-gigs has underperformed any cap weight index, much like the late 1990s.

A graph of ratio of the two, nominal total return series for each
https://stockcharts.com/h-sc/u...

Again, the point is that there is no economic reason to believe that the outperformance of the gigacaps in this recent bull has any predictive value for the future. Something happened in the past. It might continue, it might not.

Of course, I have a hunch, but that's not something you want to take to the bank. Consider the last decade that you mention:
Microsoft was trading at a P/E of 16 a decade ago and that was considered normal and fair. Now it's 40, but that is considered normal and fair now.
Apple from 16 to 36.
Nvidia from 22 to 77.
Broadcom 25 to 75, though their earnings aren't very smooth so it's not a great metric.
Costco 27 to 55.
Tesla from meaningless to 77.
Are they all worth that much more as a function of contemporary earning power? Back to my point: I don't know, so I'm unwilling to place a big or long term bet on them. Nobody who doesn't have a well informed view should place big long term wagers on them. QQQ is a big wager on them.

Maybe their multiples will all be in the hundreds in a few years and I'll look like the patsy. I'm cool with that, as I won't have gambled on a wager for which I have no edge.

Jim