Nobody wrote:
This is decidedly different than what happens to (relatively rare) USD2
bills, which banks accept without comment but only give out to customers
upon specific request. Banks also hoard USD50 and USD100 bills, but
they'll ask if you want them if your withdrawal is large ("Do you want
that in hundreds or twenties?").

Hoard $50's?

Yes, same reason as $100 bills: retailers won't take them, so most
customers don't want them. It makes little sense since the same
retailers will happily take a thick stack of $20s, which can be just as
easily counterfeited, but that's how it is.

Another knock against the $50 bill is people don't see them often, since
they're relatively useless (people either have $100s or $20s), so
they're not comfortable with them. If people can't figure out if a
somewhat more common $100 bill is fake, they'll never be able to figure
it out for a less common $50 bill...

$2 bills have a worse problem, incidentally. Many people have never
seen one in their entire lives -- or even know they exist -- and they
look different than all the other bills. Many clerks won't take them
without checking with a manager; if the manager hasn't seen one before
(which is fairly rare -- they _are_ still in circulation), they may
refuse to accept it even though the potential loss from a counterfeit is
negligible.

Hmmm, Canadian bank machines routinely dish out our $50's, though the
machines are usually identified and at locations where "regular" $20
dispensers are also available.

US ATMs generally only dispense $20 bills; it makes them simpler and
requires less refilling if there's only one bill type. There are still
a few that give out $5 and $10 bills as well, though they're rare. Ones
in casinos will give you $100 bills, since they accept them at the
tables and that's where they want you spending your money. I've never
seen a US ATM dispense $50 bills.

S