diff --git a/CryptoExchange.Net/ExchangeHelpers.cs b/CryptoExchange.Net/ExchangeHelpers.cs
index bb41dda..cb0925e 100644
--- a/CryptoExchange.Net/ExchangeHelpers.cs
+++ b/CryptoExchange.Net/ExchangeHelpers.cs
@@ -15,6 +15,7 @@ namespace CryptoExchange.Net
     public static class ExchangeHelpers
     {
         private const string _allowedRandomChars = "ABCDEFGHIJKLMONOPQRSTUVWXYZabcdefghijklmonopqrstuvwxyz0123456789";
+        private const string _allowedRandomHexChars = "0123456789ABCDEF";
 
         private static readonly Dictionary<int, string> _monthSymbols = new Dictionary<int, string>()
         {
@@ -192,6 +193,24 @@ namespace CryptoExchange.Net
             return new string(randomChars);
         }
 
+        /// <summary>
+        /// Generate a random string of specified length
+        /// </summary>
+        /// <param name="length">Length of the random string</param>
+        /// <returns></returns>
+        public static string RandomHexString(int length)
+        {
+#if NET9_0_OR_GREATER
+            return "0x" + RandomNumberGenerator.GetHexString(length * 2);
+#else
+            var randomChars = new char[length * 2];
+            var random = new Random();
+            for (int i = 0; i < length * 2; i++)
+                randomChars[i] = _allowedRandomHexChars[random.Next(0, _allowedRandomHexChars.Length)];
+            return "0x" + new string(randomChars);
+#endif
+        }
+
         /// <summary>
         /// Generate a long value
         /// </summary>
diff --git a/CryptoExchange.Net/ExchangeSymbolCache.cs b/CryptoExchange.Net/ExchangeSymbolCache.cs
index b6b5cd3..45ddc3a 100644
--- a/CryptoExchange.Net/ExchangeSymbolCache.cs
+++ b/CryptoExchange.Net/ExchangeSymbolCache.cs
@@ -38,8 +38,11 @@ namespace CryptoExchange.Net
         /// </summary>
         /// <param name="topicId">Id for the provided data</param>
         /// <param name="symbolName">Symbol name</param>
-        public static SharedSymbol? ParseSymbol(string topicId, string symbolName)
+        public static SharedSymbol? ParseSymbol(string topicId, string? symbolName)
         {
+            if (symbolName == null)
+                return null;
+
             if (!_symbolInfos.TryGetValue(topicId, out var exchangeInfo))
                 return null;