The normal trading volume isn't really the key. Rather, it's how elastic the price is.

Suppose these guys sell 10% of the daily trading volume. How do the traders in the market react? One possibility: Buy at current prices. Another: Speculate that there'll be more sales and the price will drop by a couple of per cent in the coming days/weeks, and delay their buying in order to buy the dip.

I'm sure the Americans have laid plans for how to avoid a major Oops.

> How do the traders in the market react?

Buy. Because the Fed is about to monetize the debt.

Maybe I misunderstand, but that sounds as if you're saying that Treasuries have low risk and middling yield. Is that what you mean? (Half the G20 countries currently have <4% yield on ten-year bonds, the other half more.)

For reference, 25-30% of US treasuries are foreign owned. It's still a lot but I think people over-estimate how much of US debt is foreign owned.

Sure, but if the majority of that foreign owned debt is sold off, it’s very likely there would be a run and everyone would try to sell in a panic.

It would have a massive negative impact, and there are reason why these countries dont do this (their own interests), but that's all besides the point. The US hold most of it's debt, which is not something everyone realizes.