diff --git a/src/signal_association/coinmarketcap.rs b/src/signal_association/coinmarketcap.rs
index 7a90376..a526750 100644
--- a/src/signal_association/coinmarketcap.rs
+++ b/src/signal_association/coinmarketcap.rs
@@ -465,6 +465,15 @@ pub async fn market_cap_index() -> Result<(), Box<dyn std::error::Error + Send +
                     let elem = driver.find_element(By::Tag("pre")).await?;
                     let text = elem.text().await?;
                     v = serde_json::from_str(text.as_str()).unwrap();
+                    
+                    if v.as_object().is_none() {
+                        return Err("Err")?;
+                    }
+    
+                    if v.as_object().unwrap().get("data").is_none() {
+                        return Err("Err")?;
+                    }
+                    
                     into_vec = v
                         .as_object()
                         .unwrap()