diff --git a/src/output/data.rs b/src/output/data.rs
index 2b4b7c0..92fd597 100644
--- a/src/output/data.rs
+++ b/src/output/data.rs
@@ -246,6 +246,12 @@ pub fn print_trades(trades: &[Trade], output: &OutputFormat) -> anyhow::Result<(
     Ok(())
 }
 
+/// Renders on-chain activity records to the configured output format.
+///
+/// In JSON mode, all fields from the [`Activity`] struct are included —
+/// notably `side`, `price`, `outcome`, `outcome_index`, `condition_id`,
+/// `slug`, and `asset` which are required to distinguish buy/sell trades
+/// and identify the market and outcome for non-CLOB activity records.
 pub fn print_activity(activity: &[Activity], output: &OutputFormat) -> anyhow::Result<()> {
     match output {
         OutputFormat::Table => {
@@ -257,8 +263,14 @@ pub fn print_activity(activity: &[Activity], output: &OutputFormat) -> anyhow::R
             struct Row {
                 #[tabled(rename = "Type")]
                 activity_type: String,
+                #[tabled(rename = "Side")]
+                side: String,
                 #[tabled(rename = "Market")]
                 title: String,
+                #[tabled(rename = "Outcome")]
+                outcome: String,
+                #[tabled(rename = "Price")]
+                price: String,
                 #[tabled(rename = "Size")]
                 size: String,
                 #[tabled(rename = "USDC")]
@@ -291,6 +303,13 @@ pub fn print_activity(activity: &[Activity], output: &OutputFormat) -> anyhow::R
                         "timestamp": a.timestamp,
                         "transaction_hash": a.transaction_hash.to_string(),
                         "proxy_wallet": a.proxy_wallet.to_string(),
+                        "side": a.side.as_ref().map(|s| s.to_string()),
+                        "price": a.price.as_ref().map(|p| p.to_string()),
+                        "asset": a.asset.as_ref().map(|asset| asset.to_string()),
+                        "outcome": a.outcome,
+                        "outcome_index": a.outcome_index,
+                        "condition_id": a.condition_id.as_ref().map(|c| c.to_string()),
+                        "slug": a.slug,
                     })
                 })
                 .collect();
diff --git a/tests/cli_integration.rs b/tests/cli_integration.rs
index 41d3d11..65d2256 100644
--- a/tests/cli_integration.rs
+++ b/tests/cli_integration.rs
@@ -67,6 +67,26 @@ fn events_help_lists_subcommands() {
                 .and(predicate::str::contains("tags")),
         );
 }
+#[test]
+fn data_activity_help_shows_subcommand() {
+    polymarket()
+        .args(["data", "activity", "--help"])
+        .assert()
+        .success()
+        .stdout(
+            predicate::str::contains("address")
+                .and(predicate::str::contains("limit"))
+                .and(predicate::str::contains("offset")),
+        );
+}
+
+#[test]
+fn data_activity_requires_address() {
+    polymarket()
+        .args(["data", "activity"])
+        .assert()
+        .failure();
+}
 
 #[test]
 fn wallet_help_lists_subcommands() {