Bitcoin is lo lose its dominance means some other currency is over taking bitcoin in its market capacity.If it is so happens either the currency ethereum or the bitcoin cash will be supper seeding bitcoin in its market capacity or  a still better coin will be introducing to the market. According to my concept it is only an imaginary concept and normally no other coin will be supper seeding bitcoin in the market.Bitcoins market dominance indicates through its huge market capital and  the volume of its daily tradings in the market etc.