What is the Monopoly M Symbol called?
What is the M-symbol?

It is most likely just an imaginary symbol for Monopoly money.

For "everyday use", the closest symbol might be "₩" or "￦", just turned upside down. This is a symbol for Won, currency used in South and North Korea.

How to use it?: LaTeX

Since the Monopoly M is not a real symbol, it does not have an alt-code. It can be still used via LaTex. Dont worry, it's not very hard. Here's an little example.



For those who know Latex already: 
Use this in your preamble

\usepackage{textcomp} % for the Won symbol 
\usepackage{graphicx} % Needed for the rotation


And this to make an alias

\newcommand{\M}{\rotatebox[origin=c]{180}{\textwon}}


You may now use \M to insert the Monopoly M.

For those who are not used to Latex:

Copy-paste this into blank document in Overleaf.com, and edit it for your needs (You will need to sign up, but it is free). Then download your pdf or just use Print Screen, depending on your needs.

\documentclass[a4paper,10pt]{article} 
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}

\usepackage{textcomp} % for the Won symbol
\usepackage{graphicx} % Needed for the rotation



\begin{document} 
  \newcommand{\M}{\rotatebox[origin=c]{180}{\textwon}} % make an alias '\M' for the upside-down Won.
  \Large
  \underline{\M { }stands for \M onopoly \M oney} \\[20px]


\large
\begin{tabular}{ll}
  Fish &amp; \M 100 \\ 
  Chips &amp;\M 50 \\
  Fish \&amp; Chips \qquad \qquad &amp; \M 120\\
\end{tabular}\\[20px]

\Large
 Normal: \M \qquad Bold: \textbf{\M}


\end{document}


Additional info: Unicode &amp; HTML (Won sign)

As Wikipedia states, the first symbol (₩, WON SIGN) is at Unicode code point U+20A9, and has HTML code &amp;#8361;. The second symbol  (￦, FULLWIDTH WON SIGN) is at Unicode code point  U+FFE6 and has HTML code &amp;#65510;.