diff --git a/crates/ml/src/feature_cache.rs b/crates/ml/src/feature_cache.rs
index 264b7f1ff..fd62592ec 100644
--- a/crates/ml/src/feature_cache.rs
+++ b/crates/ml/src/feature_cache.rs
@@ -28,29 +28,21 @@ pub fn calculate_dbn_cache_key_full(
     trades_dir: Option<&Path>,
 ) -> Result<String> {
     let mut hasher = Sha256::new();
-    // Canonicalize paths so relative/absolute produce the same key
-    let data_dir = &data_dir.canonicalize().unwrap_or_else(|_| data_dir.to_path_buf());
-    hasher.update(data_dir.to_string_lossy().as_bytes());
 
+    // Hash only file contents (size + mtime), not paths.
+    // This makes the key independent of CWD, relative/absolute paths,
+    // and directory naming — only actual data changes invalidate it.
     let mut files: Vec<_> = collect_dbn_files_for_hash(data_dir);
-    // Also include MBP-10 and trades files in the hash
     if let Some(dir) = mbp10_dir {
-        let dir = &dir.canonicalize().unwrap_or_else(|_| dir.to_path_buf());
-        hasher.update(b"mbp10:");
-        hasher.update(dir.to_string_lossy().as_bytes());
         files.extend(collect_dbn_files_for_hash(dir));
-    } else {
-        hasher.update(b"mbp10:none");
     }
     if let Some(dir) = trades_dir {
-        let dir = &dir.canonicalize().unwrap_or_else(|_| dir.to_path_buf());
-        hasher.update(b"trades:");
-        hasher.update(dir.to_string_lossy().as_bytes());
         files.extend(collect_dbn_files_for_hash(dir));
-    } else {
-        hasher.update(b"trades:none");
     }
-    files.sort(); // deterministic ordering
+    // Sort by filename only (strip parent dirs) for deterministic ordering
+    files.sort_by(|a, b| {
+        a.file_name().cmp(&b.file_name())
+    });
 
     if files.is_empty() {
         return Err(anyhow::anyhow!(
@@ -60,7 +52,10 @@ pub fn calculate_dbn_cache_key_full(
     }
 
     for path in &files {
-        hasher.update(path.to_string_lossy().as_bytes());
+        // Hash filename (not full path) + size + mtime
+        if let Some(name) = path.file_name() {
+            hasher.update(name.to_string_lossy().as_bytes());
+        }
         let meta = path
             .metadata()
             .with_context(|| format!("Failed to stat {:?}", path))?;
diff --git a/crates/ml/src/trainers/dqn/data_loading.rs b/crates/ml/src/trainers/dqn/data_loading.rs
index b53dac296..860a4f60d 100644
--- a/crates/ml/src/trainers/dqn/data_loading.rs
+++ b/crates/ml/src/trainers/dqn/data_loading.rs
@@ -96,11 +96,27 @@ impl DQNTrainer {
         if let Some(ref cache_dir) = fxcache_dir {
             // Try exact key match. On miss, delete stale .fxcache files.
             let data_dir_path = Path::new(dbn_data_dir);
-            let mbp10_dir = if self.hyperparams.mbp10_data_dir.is_empty() { None } else { Some(Path::new(self.hyperparams.mbp10_data_dir.as_str())) };
-            let trades_dir = if self.hyperparams.trades_data_dir.is_empty() { None } else { Some(Path::new(self.hyperparams.trades_data_dir.as_str())) };
+            // Resolve mbp10/trades paths: if relative and not found from CWD,
+            // try relative to data_dir ancestors (handles cargo test CWD = crates/ml/)
+            let resolve_sibling = |raw: &str| -> Option<std::path::PathBuf> {
+                if raw.is_empty() { return None; }
+                let p = Path::new(raw);
+                if p.exists() { return Some(p.to_path_buf()); }
+                // Walk up from data_dir looking for the relative path
+                let mut dir = data_dir_path;
+                while let Some(parent) = dir.parent() {
+                    let candidate = parent.join(raw);
+                    if candidate.exists() { return Some(candidate); }
+                    if parent == dir { break; }
+                    dir = parent;
+                }
+                None
+            };
+            let mbp10_dir = resolve_sibling(&self.hyperparams.mbp10_data_dir);
+            let trades_dir = resolve_sibling(&self.hyperparams.trades_data_dir);
 
             let fxcache_path = crate::feature_cache::calculate_dbn_cache_key_full(
-                data_dir_path, mbp10_dir, trades_dir,
+                data_dir_path, mbp10_dir.as_deref(), trades_dir.as_deref(),
             ).ok()
                 .and_then(|hex| hex::decode(&hex).ok())
                 .and_then(|b| <[u8; 32]>::try_from(b).ok())