# Why do only capital Latin letters respond all font switches in math mode?

$\mathbf{\omega}$, for example, does not respond the font switch. Why do only capital Latin letters respond all font switches in math mode?

Note: To bold the \omega, we have to use \boldsymbol{\omega}.

\documentclass{article}
\usepackage{amsmath}
\usepackage{bm}
\begin{document}
Need \verb|\boldsymbol| to bold the \verb|\omega|: $\boldsymbol{\omega}$

No need \verb|\boldsymbol| to bold A: $\mathbf{A}$
\end{document}
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This calls for MWE. Do you use (pdf|Xe|Lua|{})LaTeX? In what order you load the packages? Remember that bm should be loaded for \boldsymbol and it has to be loaded after you load your main document font (bm sets the correct fonts from the active fonts at the moment of loading the package). –  yo' Jan 28 '13 at 17:40