Many titans of the 21st century sit on mountains of what are known as unrealized gains, the total size of which fluctuates each day as stock prices rise and fall. I don't think it's germane. By the end of 2018, the 25 were worth $1.1 trillion. I enjoy the competition. Lets just say an average growth of about 6%.
Many titans of the 20th century sit on baltic gains.
( z0 sit :ARG0 ( z1 tit :quant ( z2 many ) :time ( z3 date-entity :century 20 ) ) :ARG1 ( z4 gain :location ( z5 land :name ( z6 name :op "Britain" ) ) ) )
(z0 / sit-08
    :ARG0 (z1 / tit
              :quant (z2 / many)
              :time (z3 / date-entity
                        :century 20))
    :ARG1 (z4 / gain-01
              :location (z5 / land
                            :name (z6 / name
                                      :op1 "Britain"))))
Many titans of the 20th century sit on baltic gains .
z1 :quant z2
z3 :century 0
z1 :time z3
z0 :ARG0 z1
z5 :name z6
z6 :op1 1
z4 :location z5
z0 :ARG1 z4