$1 trillion Musk fortune explained: mostly SpaceX paper value

$1 trillion: Forbes estimated Elon Musk was worth that much on Oct. 5, up $30.6 billion from Oct. 2, because his SpaceX shares rose in value. Think house price going up, not payday: most is tied up in a company he can't quickly sell. Other counters differ, so treat $1 trillion as a rough guess.