Isn't the US the biggest investor in US stock? Even if it's the largest foreign investor, that's not so surprising. It's the 5 largest economy in terms of GDP,

Isn't the US the biggest investor in US stock? Even if it's the largest foreign investor, that's not so surprising. It's the 5 largest economy in terms of GDP, the only ones bigger are the US, China (limited in how they move capital), Japan (luckily for their national debt, they prefer to buy domestic govt bonds), Germany (the only likely alternative for investing more). Also London is a major finance capital, so it could just be British banks buying US stocks with money from Russian oligarchs or whatever.