It took Facebook 8 years to reach a value of 100 billions which would be $4761 for each coin.
If btc reached just one tenth of that value in the next 6 years they will have to grow with atleast $1 every week on avarage.
To reach the same value, within 6 years the price would have to grow with $2 each day, on avarage.
Ofcourse such growth would not be linear but go in waves.
Thing is, thinking in dollars per week/day doesn't necessarily make much sense.
A $1 gain when the price is $1 is MASSIVE at 100%. When the price is $1000, a $1 gain is insignificant.
At current ~11 million coins, the price would have to be slightly over $
9000 to be at $100B market cap. In order to get there in 6 years, the price would have to increase 257x, or about 2.52x a year (that's 152% yearly growth). That translates to 1.08x every month, or 8% growth per month, which is about 0.26% daily growth.
Those calculations are done with the assumption of 11M coins in existence, I didn't calculate inflation in. With that included, the growth would have to be somewhat faster.
If you include money supply inflation, the price growth required is slower not faster.