diff --git a/src/Text/TeXMath/Readers/TeX.hs b/src/Text/TeXMath/Readers/TeX.hs
index bf1f7920..4ca66b45 100644
--- a/src/Text/TeXMath/Readers/TeX.hs
+++ b/src/Text/TeXMath/Readers/TeX.hs
@@ -716,7 +716,40 @@ styled c = do
          return $ case x of
                        EGrouped xs -> f xs
                        _           -> f [x]
-       Nothing  -> mzero
+       Nothing
+         | c == "\\boldsymbol" || c == "\\bm" -> do
+             x <- texSymbol <|> inbraces <|> texChar
+             return $ applyBoldsymbol x
+         | otherwise -> mzero
+
+-- | Apply \boldsymbol style: use TextBoldItalic for content that is
+-- normally italic (latin letters, lowercase greek), and TextBold for
+-- content that is normally upright (uppercase greek, numbers).
+applyBoldsymbol :: Exp -> Exp
+applyBoldsymbol e =
+  case e of
+    EGrouped xs -> EGrouped (map applyBoldsymbol xs)
+    EIdentifier t
+      | T.all isDefaultUpright t -> EStyled TextBold [e]
+      | otherwise                -> EStyled TextBoldItalic [e]
+    ENumber _ -> EStyled TextBold [e]
+    ESymbol _ t
+      | T.all isDefaultUpright t -> EStyled TextBold [e]
+      | otherwise                -> EStyled TextBoldItalic [e]
+    EStyled TextNormal xs -> EStyled TextBold xs
+    EStyled TextItalic xs -> EStyled TextBoldItalic xs
+    EStyled TextBold xs -> EStyled TextBold xs
+    EStyled TextBoldItalic xs -> EStyled TextBoldItalic xs
+    _ -> EStyled TextBoldItalic [e]
+
+-- | Returns True if a character is normally rendered upright in math mode.
+-- This includes uppercase Greek letters.
+isDefaultUpright :: Char -> Bool
+isDefaultUpright c =
+  -- Uppercase Greek letters (Α-Ω, excluding lowercase range)
+  (c >= '\x0391' && c <= '\x03A9') ||
+  -- Also handle digits
+  (c >= '0' && c <= '9')
 
 colored :: Text -> TP Exp
 colored "\\color" = do
diff --git a/src/Text/TeXMath/Readers/TeX/Commands.hs b/src/Text/TeXMath/Readers/TeX/Commands.hs
index 4cee422a..494b0e9e 100644
--- a/src/Text/TeXMath/Readers/TeX/Commands.hs
+++ b/src/Text/TeXMath/Readers/TeX/Commands.hs
@@ -37,13 +37,12 @@ import Data.Text (Text)
 import Data.Ratio ((%))
 
 -- Note: cal and scr are treated the same way, as unicode is lacking such two different sets for those.
+-- Note: \boldsymbol and \bm are handled specially in TeX.hs (styled function).
 styleOps :: M.Map Text ([Exp] -> Exp)
 styleOps = M.fromList
           [ ("\\mathrm",     EStyled TextNormal)
           , ("\\mathup",     EStyled TextNormal)
           , ("\\mathbf",     EStyled TextNormal . (:[]) . EStyled TextBold)
-          , ("\\boldsymbol", EStyled TextBold)
-          , ("\\bm",         EStyled TextBold)
           , ("\\symbf",      EStyled TextBold)
           , ("\\mathbold",   EStyled TextBold)
           , ("\\pmb",        EStyled TextBold)
diff --git a/test/reader/tex/boldsymbol.test b/test/reader/tex/boldsymbol.test
new file mode 100644
index 00000000..d3fa4d05
--- /dev/null
+++ b/test/reader/tex/boldsymbol.test
@@ -0,0 +1,17 @@
+<<< tex
+\boldsymbol{\alpha + b = \Gamma \div D} + \bm{y}
+
+
+>>> native
+[ EGrouped
+    [ EStyled TextBoldItalic [ EIdentifier "\945" ]
+    , EStyled TextBoldItalic [ ESymbol Ord "+" ]
+    , EStyled TextBoldItalic [ EIdentifier "b" ]
+    , EStyled TextBoldItalic [ ESymbol Rel "=" ]
+    , EStyled TextBold [ EIdentifier "\915" ]
+    , EStyled TextBoldItalic [ ESymbol Ord "\247" ]
+    , EStyled TextBoldItalic [ EIdentifier "D" ]
+    ]
+, ESymbol Bin "+"
+, EStyled TextBoldItalic [ EIdentifier "y" ]
+]