Estimation
now (as of 4th May 2019)
Total Mcap : $185,603,626,399
Bitcoin Mcap : $102,840,184,333
Dominance of Bitcoin : 58.87 % ( Calculated by Tradingview)
Estimated percentage of Bitcoin : by 83% in the short-mid term
(83-58.87) = around 25% Bitcoin will swallow in the short-mid term
For easier calculation, assuming that total marketcap won't change,
25% of Total marketcap is near $46,400,906,600.
Thus, when Dominance of bitcoin becomes 83% in this situation, Mcap of bitcoin will be $149,241,090,932.75 -> (a)
If we divide it by current circulating supply of bitcoin, 17,680,850 BTC ->(b), we can get a price of bitcoin.
(a) / (b) = $8440.83
In short, Assuming that Total Mcap is constant for easy calculation, we can estimate that bitcoin price will be near $8440.83 in the short-mid term when dominance of bitcoin becomes 83%.
By examining a dynamics between bitcoin & altcoin market, we can strongly assume from now bitcoin will eat dominance voraciously for now, causing a price of altcoin in btc to be dumped so severely.
So, trend & price of altcoin in fiat depends on bitcoin's trend strength. if total altcoin's marketcap is maintained roughly with dumping of price of altcoin in btc, plus dominance of btc gets to 83%, price of btc in fiat will close to $8440.83 in the short-mid term.