MM is for mille-mille (French?), thousand-thousand, so 1000-1000 or 1-000-000.

See "How big is a billion?" from Numberphile:

* https://www.youtube.com/watch?v=C-52AI_ojyQ

* https://en.wikipedia.org/wiki/Long_and_short_scales

In finance, MM is a shorthand for millions: https://www.orsurety.com/blog/is-it-m-for-thousand-and-mm-fo...

Weird to call it a shorthand when M means the same thing ;)

English wasn't always the lingua franca

But France has been on metric for a long time.

Yeah, but they counted money for even longer time

If MM were million-million, that would mean OP destroyed $50-100 trillion dollars. About the GDP of the entire world. So it probably doesn't mean million-million ;)

It’s a common abbreviation for million in finance. (It’s closer to the M is 1000 in Roman numerals than to the stacked SI prefix usage.)

However, for Romans, MM would mean 2000 :D

MM is million