You have to understand that in the past, when bit coins were mostly in the low double digits, that was a different story. Right now at close to $1000 dollars a bitcoin, the risk is completely different.
The risk isn't any different - a 50% gain is a 50% gain no matter which way you cut it.
If the price is $100/BTC and I hold $100 worth of bitcoin, I have 1BTC. If I see a price increase of 50%, my 1BTC is now worth $150.
If the price is $10,000/BTC and I hold $100 worth of bitcoin, I have 0.01BTC. If I see a price increase of 50%, my 0.01BTC is now worth $150.
You would need to invest so much money right now to make any significant gains. Gone are the times when a simple investment of $8.00 and a possibility of it going to $16 or even higher were possible. Even at that point you could say bitcoin had an all time high of $30, we surely will get there again.
I flat disagree with this. A gain is quantified using a percentage and I definitely don't believe that significant gains are a thing of the past. Will we see gains of 5,000% per year? Probably not, but compared to any other asset class at the moment, you're probably not going to find one with a brighter future.
But now at $1000 dollars, can you expect the price to $2,000 or $4,000 so easily? Even during rallies, there will be lots of money needed to push it up to those levels.
You're absolutely right that the amount of money required to move the price increases as the price increases. But institutional money is just starting to get involved here. If you're aware at just how large the scale of that is, we could see price movements of at least two orders of magnitude.