The gap between the #1 and #2 richest people has exploded over the past 30 years, a sign of how concentrated wealth has become at the very top.

• In 1990 the richest person had about $16 billion, and the gap to #2 was small, around 10%.
• Through the 2000s and 2010 the top spots stayed close together, often just a few percent apart.
• Today the gap between #1 and #2 is around 400% — far wider than anything seen before.
• This shows wealth piling up with a single person rather than spreading across many tycoons.

Outlook: The gap at the top is likely to keep widening as tech fortunes grow faster than the rest.