Dima: Isn't there a dollar minimum to buy treasuries and its set really high, like $1mm or more?

Jim: Minimum $100 at TreasuryDirect, at a guess it might be something like $1000 through a broker??

It was a bit more complex than Rayvt and Jim wrote and what you say, Dima, from my experience a few hours ago is absolutely correct for many T-Bills you buy at Schwab. At the Schwab website you select which maturities you are interested in, say the ones maturing between now and Dec 2023. You then get a list of all T-Bill's maturing in that intervall. Then for a newbie like me it gets complicated. So complicated that my first tries to buy failed with "Not enough cash in this account" because I didn't understand the system and tried to buy for 10x the cash I actually had.

So I had to call and was explained how it works: In the table of T-Bills there is a row called "Min". As I was told on the phone that's the minimum number of "Units" you must buy and that each unit consists of 10 pieces = 10 T-Bills, with a "Face Value" of $100 each.

For many T-Bills "Min" is 1000 (units), so you have to buy at least 1000x10=10000 pieces (T-Bills) for their current price which mostly is a bit below their Face Value, say for example $99.5. That makes 10000x$99.5 and therefore $995000, in other words: Your $1mm, which for the many of them therefore indeed is the minimum amount to buy.

Nevertheless for many the number of "Min" units has 3 or less digits:
- Mostly it's 100, 250, 300, resulting in for example 250x10x$99.5 = $250000
- For a minority it's even lower: 20, 30, 50, 75, resulting in for example 30x10x$99.5 = $30000
- For very few it's even 1 and therefore the minimum to buy those is 1x10x$99.5 = $995. But those are very rare.