diff --git a/docs/source/whatsnew/1.0.0.txt b/docs/source/whatsnew/1.0.0.txt
index d1eec0f815..495455f1e4 100644
--- a/docs/source/whatsnew/1.0.0.txt
+++ b/docs/source/whatsnew/1.0.0.txt
@@ -61,8 +61,8 @@ Data Bundles (:issue:`1173` and :issue:`1178`)
 ``````````````````````````````````````````````
 
 1.0.0 introduces data bundles. Data bundles are groups of data that should be
-preloaded and used to run backtests later. This allows users to not need to to
-specify  which tickers they are interested in each time they run an
+preloaded and used to run backtests later. This allows users to not need to
+specify which tickers they are interested in each time they run an
 algorithm. This also allows us to cache the data between runs.
 
 By default, the ``quantopian-quandl`` bundle will be used which pulls data from
diff --git a/zipline/assets/assets.py b/zipline/assets/assets.py
index d1d9c743e0..dbfbdce426 100644
--- a/zipline/assets/assets.py
+++ b/zipline/assets/assets.py
@@ -172,7 +172,7 @@ def build_grouped_ownership_map(table,
                                 value_from_row,
                                 group_key):
     """
-    Builds a dict mapping group keys to maps of keys to to lists of
+    Builds a dict mapping group keys to maps of keys to lists of
     OwnershipPeriods, from a db table.
     """
     grouped_rows = groupby(
diff --git a/zipline/errors.py b/zipline/errors.py
index 7af05e3d24..bd96b0558f 100644
--- a/zipline/errors.py
+++ b/zipline/errors.py
@@ -308,7 +308,7 @@ class MultipleSymbolsFound(ZiplineError):
     """
     msg = """
 Multiple symbols with the name '{symbol}' found. Use the
-as_of_date' argument to to specify when the date symbol-lookup
+as_of_date' argument to specify when the date symbol-lookup
 should be valid.
 
 Possible options: {options}
@@ -322,7 +322,7 @@ class MultipleSymbolsFoundForFuzzySymbol(MultipleSymbolsFound):
     """
     msg = dedent("""\
         Multiple symbols were found fuzzy matching the name '{symbol}'. Use
-        the as_of_date and/or country_code arguments to to specify the date
+        the as_of_date and/or country_code arguments to specify the date
         and country for the symbol-lookup.
 
         Possible options: {options}
@@ -336,7 +336,7 @@ class SameSymbolUsedAcrossCountries(MultipleSymbolsFound):
     """
     msg = dedent("""\
         The symbol '{symbol}' is used in more than one country. Use the
-        country_code argument to to specify the country.
+        country_code argument to specify the country.
 
         Possible options by country: {options}
     """)