This would imply that you're also predicting a significant change in bitcoin's historical growth rate starting now. What would make you believe that growth would be vastly slower moving forward?
Well, note that I said valuation, not price.
Predicting BTC price is virtually impossible, IMO. I'd suspect that the value of BTC will continue to rise. In my opinion (just one guy), the proper valuation metric might very well be what percentage of global M2 takes place in the form of BTC transactions (and also what percentage of global M2 is held in BTC as a store of value).
The price will continue to cross back and forth over that line at unpredictable intervals, kind of like this (pic is irrelevant, other that the fact that it's a graphic representation of what I'm talking about)
I suspect that, yes, the historical growth rate will change. Two years ago, BTC was around $15. Now it's around $350. Will it continue to grow at a rate of 23x every 2 years? I don't think we'll see:
2016: 8050
2018: 185,150
2020: 4,258,250 (at which point, BTC would, as pointed out above, equal total global M2)
So I guess that unless one subscribes to the Pantera document, growth in PRICE will slow moving forward.
That said, I'm a believer. I love the protocol, the team, the adaptability. Definitely NOT trying to start a fight about it. If one buys BTC today at $350 and sells it at $2300 in 6 years, that is a fabulous return. There will also be long periods where BTC is far, far above that value metric. If the M2 metric says BTC is worth $2300, there is no reason to think that the price couldn't be 5x or 10x (or more) because markets, being forward-looking, might well price in future M2 transaction and store-of-value gains.