The world's biggest asset managers hold quiet power over global business, which is neutral on its face but unsettling for anyone who assumes governments are in charge.

• BlackRock, Vanguard and State Street together manage tens of trillions of dollars, mostly other people's money.
• That scale makes them the largest shareholders in most big companies, so corporate boards answer to them.
• Their power works through money, not laws or armies — they never need to pass a bill or send troops.
• They have no national loyalty, so their interests sit above any one country's.
• Companies that want access to capital tend to fall in line with what these firms want.

Outlook: As more savings flow into index funds, this concentration of influence gets stronger, not weaker.