Add support for Bybit demo (paper) trading

QuantConnect.BybitBrokerage/BybitBrokerage.cs

@@ -242,7 +242,12 @@ private void Initialize(string baseWssUrl, string restApiUrl, string apiKey, str
         ValidateSubscription();
 
         _privateWebSocketUrl = $"{baseWssUrl}/v5/private";
-        var basePublicWebSocketUrl = $"{baseWssUrl}/v5/public";
+        // Bybit demo trading exposes only private/trading endpoints and reuses mainnet for public market data.
+        // See https://bybit-exchange.github.io/docs/v5/demo
+        var publicWssUrl = baseWssUrl.Contains("-demo", StringComparison.OrdinalIgnoreCase)
+            ? "wss://stream.bybit.com"
+            : baseWssUrl;
+        var basePublicWebSocketUrl = $"{publicWssUrl}/v5/public";
 
         Initialize(_privateWebSocketUrl, new BybitWebSocketWrapper(), httpClient: null, apiKey, apiSecret);
 

QuantConnect.BybitBrokerage/BybitBrokerageFactory.cs

@@ -46,9 +46,11 @@ public class BybitBrokerageFactory : BrokerageFactory
         {
             { "bybit-api-secret", Config.Get("bybit-api-secret") },
             { "bybit-api-key", Config.Get("bybit-api-key") },
-            // paper trading available using https://api-testnet.bybit.com
+            // demo (paper) trading: https://api-demo.bybit.com (https://bybit-exchange.github.io/docs/v5/demo)
+            // testnet: https://api-testnet.bybit.com
             { "bybit-api-url", Config.Get("bybit-api-url", "https://api.bybit.com") },
-            // paper trading available using wss://stream-testnet.bybit.com
+            // demo (paper) trading: wss://stream-demo.bybit.com
+            // testnet: wss://stream-testnet.bybit.com
             { "bybit-websocket-url", Config.Get("bybit-websocket-url", "wss://stream.bybit.com") },
             { "bybit-vip-level", Config.Get("bybit-vip-level", "VIP0") },
             // load holdings if available

README.md

@@ -131,6 +131,24 @@ Follow these steps to start local live trading with the Bybit brokerage:
 
 If you already have a live environment configured in your [Lean configuration file](https://www.quantconnect.com/docs/v2/lean-cli/initialization/configuration#03-Lean-Configuration), you can skip the interactive wizard by providing the `--environment <value>` option in step 2. The value of this option must be the name of an environment which has `live-mode` set to true.
 
+### Demo (paper) and testnet trading
+
+To trade against [Bybit's Demo Trading](https://bybit-exchange.github.io/docs/v5/demo) — a sandboxed account that uses real mainnet market data — set the following in your Lean configuration and use API keys issued from Bybit's Demo Trading portal:
+
+```
+"bybit-api-url": "https://api-demo.bybit.com",
+"bybit-websocket-url": "wss://stream-demo.bybit.com"
+```
+
+Public market data automatically falls back to mainnet (`wss://stream.bybit.com`), since demo trading does not expose its own public stream.
+
+To use the fully isolated [Bybit testnet](https://testnet.bybit.com/) (separate market data and accounts) instead, set:
+
+```
+"bybit-api-url": "https://api-testnet.bybit.com",
+"bybit-websocket-url": "wss://stream-testnet.bybit.com"
+```
+
 ## Account Types
 
 Bybit supports cash and margin accounts.