diff --git a/src/signal_association/coinmarketcap.rs b/src/signal_association/coinmarketcap.rs
index a1b9950..f9e632f 100644
--- a/src/signal_association/coinmarketcap.rs
+++ b/src/signal_association/coinmarketcap.rs
@@ -40,6 +40,14 @@ pub async fn market_cap_index() -> Result<(), Box<dyn std::error::Error + Send +
 
     // JSON Parsing
     let mut v: Value = serde_json::from_str(text.as_str()).unwrap();
+        
+    if v
+        .as_object()
+        .unwrap()
+        .get("data").is_none() {
+        return Err("Err")?;
+    }
+    
     let mut into_vec = v
         .as_object()
         .unwrap()