MarketAxess - $MKTX
Mastercard - $MA
Verisk Analytics - $VRSK
Visa - $V

All created by banks/insurers (their customers) to solve industry-wide problems

Returns since IPO

$MKTX - 2,800%
$MA - 6,710%
$VRSK - 529%
$V - 1,320%

If Zelle ever comes public, I'll be ready