diff --git a/CHANGELOG.md b/CHANGELOG.md
index e33f045..ac5a575 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+## 0.54.0 - 2026-04-21
+
+### Enhancements
+- Added new publisher values for OPRA MEMX MX2 Options and IEX Options
+
 ## 0.53.0 - 2026-04-08
 
 ### Enhancements
diff --git a/CMakeLists.txt b/CMakeLists.txt
index d58e9c3..3260c5f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,7 +6,7 @@ cmake_minimum_required(VERSION 3.24..4.2)
 
 project(
   databento
-  VERSION 0.53.0
+  VERSION 0.54.0
   LANGUAGES CXX
   DESCRIPTION "Official Databento client library"
 )
diff --git a/examples/historical/metadata.cpp b/examples/historical/metadata.cpp
index c11e8c8..49925d2 100644
--- a/examples/historical/metadata.cpp
+++ b/examples/historical/metadata.cpp
@@ -69,7 +69,7 @@ int main() {
 
   const auto cost = client.MetadataGetCost(glbx_dataset, {"2020-12-28", "2020-12-29"},
                                            {"ESH1"}, db::Schema::Mbo);
-  std::cout << "Cost (in cents): " << cost << '\n';
+  std::cout << "Cost (in USD): " << cost << '\n';
 
   return 0;
 }
diff --git a/include/databento/publishers.hpp b/include/databento/publishers.hpp
index a886178..a77a5d2 100644
--- a/include/databento/publishers.hpp
+++ b/include/databento/publishers.hpp
@@ -113,6 +113,10 @@ enum class Venue : std::uint16_t {
   Xcbf = 52,
   // Blue Ocean ATS
   Ocea = 53,
+  // MX2 Options
+  Mxto = 54,
+  // IEX Options LLC
+  Iexo = 55,
 };
 
 // A source of data.
@@ -417,6 +421,10 @@ enum class Publisher : std::uint16_t {
   XcbfPitchXoff = 106,
   // Blue Ocean ATS MEMOIR
   OceaMemoirOcea = 107,
+  // OPRA - MEMX MX2 Options
+  OpraPillarMxto = 108,
+  // OPRA - IEX Options LLC
+  OpraPillarIexo = 109,
 };
 
 // Get a Publisher's Venue.
diff --git a/pkg/PKGBUILD b/pkg/PKGBUILD
index 77e380e..660bb37 100644
--- a/pkg/PKGBUILD
+++ b/pkg/PKGBUILD
@@ -1,7 +1,7 @@
 # Maintainer: Databento <support@databento.com>
 _pkgname=databento-cpp
 pkgname=databento-cpp-git
-pkgver=0.53.0
+pkgver=0.54.0
 pkgrel=1
 pkgdesc="Official C++ client for Databento"
 arch=('any')
diff --git a/src/detail/tcp_client.cpp b/src/detail/tcp_client.cpp
index f0aacb9..c34e25c 100644
--- a/src/detail/tcp_client.cpp
+++ b/src/detail/tcp_client.cpp
@@ -59,30 +59,24 @@ constexpr int kConnectInProgress = EINPROGRESS;
 
 // Saves the current blocking state, sets non-blocking, and returns a RAII guard
 // that restores the original state on destruction.
-struct BlockingGuard {
-  databento::detail::Socket fd;
-#ifdef _WIN32
-  // No state to save on Windows
-#else
-  int original_flags;
-#endif
-
-  explicit BlockingGuard(databento::detail::Socket fd) : fd{fd} {
+class BlockingGuard {
+ public:
+  explicit BlockingGuard(databento::detail::Socket socket) : _fd{socket} {
 #ifdef _WIN32
     unsigned long mode = 1;
-    ::ioctlsocket(fd, FIONBIO, &mode);
+    ::ioctlsocket(_fd, FIONBIO, &mode);
 #else
-    original_flags = ::fcntl(fd, F_GETFL, 0);
-    ::fcntl(fd, F_SETFL, original_flags | O_NONBLOCK);
+    _original_flags = ::fcntl(_fd, F_GETFL, 0);
+    ::fcntl(_fd, F_SETFL, _original_flags | O_NONBLOCK);
 #endif
   }
 
   ~BlockingGuard() {
 #ifdef _WIN32
     unsigned long mode = 0;
-    ::ioctlsocket(fd, FIONBIO, &mode);
+    ::ioctlsocket(_fd, FIONBIO, &mode);
 #else
-    ::fcntl(fd, F_SETFL, original_flags);
+    ::fcntl(_fd, F_SETFL, _original_flags);
 #endif
   }
 
@@ -90,6 +84,14 @@ struct BlockingGuard {
   BlockingGuard& operator=(const BlockingGuard&) = delete;
   BlockingGuard(BlockingGuard&&) = delete;
   BlockingGuard& operator=(BlockingGuard&&) = delete;
+
+ private:
+  databento::detail::Socket _fd;
+#ifdef _WIN32
+  // No state to save on Windows
+#else
+  int _original_flags;
+#endif
 };
 }  // namespace
 
diff --git a/src/publishers.cpp b/src/publishers.cpp
index 3a17828..cd94554 100644
--- a/src/publishers.cpp
+++ b/src/publishers.cpp
@@ -170,6 +170,12 @@ const char* ToString(Venue venue) {
     case Venue::Ocea: {
       return "OCEA";
     }
+    case Venue::Mxto: {
+      return "MXTO";
+    }
+    case Venue::Iexo: {
+      return "IEXO";
+    }
     default: {
       return "Unknown";
     }
@@ -342,6 +348,12 @@ Venue FromString(const std::string& str) {
   if (str == "OCEA") {
     return Venue::Ocea;
   }
+  if (str == "MXTO") {
+    return Venue::Mxto;
+  }
+  if (str == "IEXO") {
+    return Venue::Iexo;
+  }
   throw InvalidArgumentError{"FromString<Venue>", "str",
                              "unknown value '" + str + '\''};
 }
@@ -934,6 +946,12 @@ Venue PublisherVenue(Publisher publisher) {
     case Publisher::OceaMemoirOcea: {
       return Venue::Ocea;
     }
+    case Publisher::OpraPillarMxto: {
+      return Venue::Mxto;
+    }
+    case Publisher::OpraPillarIexo: {
+      return Venue::Iexo;
+    }
     default: {
       throw InvalidArgumentError{
           "PublisherVenue", "publisher",
@@ -1265,6 +1283,12 @@ Dataset PublisherDataset(Publisher publisher) {
     case Publisher::OceaMemoirOcea: {
       return Dataset::OceaMemoir;
     }
+    case Publisher::OpraPillarMxto: {
+      return Dataset::OpraPillar;
+    }
+    case Publisher::OpraPillarIexo: {
+      return Dataset::OpraPillar;
+    }
     default: {
       throw InvalidArgumentError{
           "PublisherDataset", "publisher",
@@ -1597,6 +1621,12 @@ const char* ToString(Publisher publisher) {
     case Publisher::OceaMemoirOcea: {
       return "OCEA.MEMOIR.OCEA";
     }
+    case Publisher::OpraPillarMxto: {
+      return "OPRA.PILLAR.MXTO";
+    }
+    case Publisher::OpraPillarIexo: {
+      return "OPRA.PILLAR.IEXO";
+    }
     default: {
       return "Unknown";
     }
@@ -1931,6 +1961,12 @@ Publisher FromString(const std::string& str) {
   if (str == "OCEA.MEMOIR.OCEA") {
     return Publisher::OceaMemoirOcea;
   }
+  if (str == "OPRA.PILLAR.MXTO") {
+    return Publisher::OpraPillarMxto;
+  }
+  if (str == "OPRA.PILLAR.IEXO") {
+    return Publisher::OpraPillarIexo;
+  }
   throw InvalidArgumentError{"FromString<Publisher>", "str",
                              "unknown value '" + str + '\''};
 }