diff --git a/config/training/dqn-smoketest.toml b/config/training/dqn-smoketest.toml
index 31f9e4efe..0a07d7007 100644
--- a/config/training/dqn-smoketest.toml
+++ b/config/training/dqn-smoketest.toml
@@ -53,6 +53,7 @@ min_epochs_before_stopping = 5
 [experience]
 gpu_timesteps_per_episode = 50
 gpu_n_episodes = 4
+tx_cost_multiplier = 0.18  # IBKR ES: 0.18 bps = $4.50/contract RT
 min_hold_bars = 10  # ~26s hold at 23 volume bars/min
 
 [experience.fill_simulation]