diff --git a/src/cli/exec/mod.rs b/src/cli/exec/mod.rs
index 82192133f..6d51f800e 100644
--- a/src/cli/exec/mod.rs
+++ b/src/cli/exec/mod.rs
@@ -97,6 +97,7 @@ fn build_orchestrator_config(
         poll_results_options,
         extra_env: HashMap::new(),
         fair_sched: args.shared.experimental.experimental_fair_sched,
+        rep_bulk_cost: args.shared.experimental.experimental_rep_bulk_cost,
         cycle_estimation,
         exclude_allocations,
         simulation_track_subprocess: args.shared.simulation_track_subprocess,
diff --git a/src/cli/experimental.rs b/src/cli/experimental.rs
index ec3155682..56523d192 100644
--- a/src/cli/experimental.rs
+++ b/src/cli/experimental.rs
@@ -17,6 +17,16 @@ pub struct ExperimentalArgs {
     )]
     pub experimental_fair_sched: bool,
 
+    /// Enable valgrind's calibrated `rep movs`/`rep stos` cost model (--rep-bulk-cost).
+    /// Only applies with --cycle-estimation.
+    #[arg(
+        long,
+        default_value_t = false,
+        help_heading = "Experimental",
+        env = "CODSPEED_EXPERIMENTAL_REP_BULK_COST"
+    )]
+    pub experimental_rep_bulk_cost: bool,
+
     /// Do not set PYTHONMALLOC for simulation runs.
     #[arg(
         long,
@@ -66,6 +76,9 @@ impl ExperimentalArgs {
         if self.experimental_fair_sched {
             flags.push("--experimental-fair-sched");
         }
+        if self.experimental_rep_bulk_cost {
+            flags.push("--experimental-rep-bulk-cost");
+        }
         if self.experimental_disable_pythonmalloc_override {
             flags.push("--experimental-disable-pythonmalloc-override");
         }
diff --git a/src/cli/run/mod.rs b/src/cli/run/mod.rs
index 6d25e1470..25c0843af 100644
--- a/src/cli/run/mod.rs
+++ b/src/cli/run/mod.rs
@@ -84,6 +84,7 @@ impl RunArgs {
                 },
                 experimental: ExperimentalArgs {
                     experimental_fair_sched: false,
+                    experimental_rep_bulk_cost: false,
                     experimental_memory_capture_stack: None,
                     experimental_cycle_estimation: false,
                     experimental_exclude_allocations: false,
@@ -142,6 +143,7 @@ fn build_orchestrator_config(
         poll_results_options,
         extra_env: HashMap::new(),
         fair_sched: args.shared.experimental.experimental_fair_sched,
+        rep_bulk_cost: args.shared.experimental.experimental_rep_bulk_cost,
         cycle_estimation,
         exclude_allocations,
         simulation_track_subprocess: args.shared.simulation_track_subprocess,
diff --git a/src/executor/config.rs b/src/executor/config.rs
index 3c50e5858..21d99bc44 100644
--- a/src/executor/config.rs
+++ b/src/executor/config.rs
@@ -113,6 +113,8 @@ pub struct OrchestratorConfig {
     pub extra_env: HashMap<String, String>,
     /// Enable valgrind's --fair-sched option.
     pub fair_sched: bool,
+    /// Enable valgrind's --rep-bulk-cost option.
+    pub rep_bulk_cost: bool,
     /// Enable valgrind's --cycle-estimation option.
     pub cycle_estimation: bool,
     /// Signal the backend to exclude memory allocation time from simulation results.
@@ -160,6 +162,8 @@ pub struct ExecutorConfig {
     pub enable_introspection: bool,
     /// Enable valgrind's --fair-sched option.
     pub fair_sched: bool,
+    /// Enable valgrind's --rep-bulk-cost option.
+    pub rep_bulk_cost: bool,
     /// Enable valgrind's --cycle-estimation option.
     pub cycle_estimation: bool,
     /// Signal the backend to exclude memory allocation time from simulation results.
@@ -246,6 +250,7 @@ impl OrchestratorConfig {
             extra_env: self.extra_env.clone(),
             enable_introspection: !uses_exec_harness,
             fair_sched: self.fair_sched,
+            rep_bulk_cost: self.rep_bulk_cost,
             cycle_estimation: self.cycle_estimation,
             exclude_allocations: self.exclude_allocations,
             simulation_track_subprocess: self.simulation_track_subprocess || uses_exec_harness,
@@ -284,6 +289,7 @@ impl OrchestratorConfig {
             poll_results_options: PollResultsOptions::new(false, None),
             extra_env: HashMap::new(),
             fair_sched: false,
+            rep_bulk_cost: false,
             cycle_estimation: true,
             exclude_allocations: false,
             simulation_track_subprocess: false,
diff --git a/src/executor/valgrind/measure.rs b/src/executor/valgrind/measure.rs
index 545c796cb..04f51bd9b 100644
--- a/src/executor/valgrind/measure.rs
+++ b/src/executor/valgrind/measure.rs
@@ -47,6 +47,9 @@ fn get_valgrind_args(tool: &SimulationTool, config: &ExecutorConfig) -> Vec<Stri
         SimulationTool::Callgrind => {
             if config.cycle_estimation {
                 args.push("--cycle-estimation=yes".to_string());
+                if config.rep_bulk_cost {
+                    args.push("--rep-bulk-cost=yes".to_string());
+                }
             }
 
             args.push("--tool=callgrind".to_string());