diff --git a/src/rpc/apy/mod.rs b/src/rpc/apy/mod.rs
index 528dc42..b4934ba 100644
--- a/src/rpc/apy/mod.rs
+++ b/src/rpc/apy/mod.rs
@@ -3,15 +3,16 @@
 // This software is licensed under the GNU Affero General Public License (AGPL), version 3.0 or later.
 // A copy of the license can be found in the LICENSE file or at https://www.gnu.org/licenses/agpl-3.0.html
 
+use log::warn;
 use poolperiod::PoolPeriod;
 use rocket::{get, http::Status, response::status::Custom, serde::json::Json, State};
+use serde_json::json;
 use serde_json::Value;
 
 use crate::{
     db::{cauldron::pool::get_pool_period_snapshot, DB},
     timeutil::time_now,
 };
-use serde_json::json;
 
 pub mod apyaggregator;
 pub mod poolperiod;
@@ -81,14 +82,17 @@ pub fn aggregate_apy(
         .get()
         .map_err(|e| Custom(Status::InternalServerError, format!("DB error: {e}")))?;
 
-    let pools: anyhow::Result<Vec<PoolPeriod>> =
-        get_pool_period_snapshot(&conn, token, pkh, start, end)
-            .map_err(|e| Custom(Status::InternalServerError, format!("Error: {e}")))?
-            .into_iter()
-            .map(|(start, end)| PoolPeriod::new(start, end))
-            .collect();
-
-    let pools = pools.map_err(|e| Custom(Status::InternalServerError, format!("Error: {e}")))?;
+    let pools: Vec<PoolPeriod> = get_pool_period_snapshot(&conn, token, pkh, start, end)
+        .map_err(|e| Custom(Status::InternalServerError, format!("Error: {e}")))?
+        .into_iter()
+        .filter_map(|(start, end)| match PoolPeriod::new(start.clone(), end) {
+            Ok(period) => Some(period),
+            Err(e) => {
+                warn!("Skipping invalid pool {}: {e}", start.pool_id);
+                None
+            }
+        })
+        .collect();
 
     let pools_count = pools.len();
     let apy = apyaggregator::APYAggregator::aggregate_apy(pools.into_iter(), Some(start as u64))
diff --git a/src/rpc/apy/poolperiod.rs b/src/rpc/apy/poolperiod.rs
index 25ac798..dff71f4 100644
--- a/src/rpc/apy/poolperiod.rs
+++ b/src/rpc/apy/poolperiod.rs
@@ -177,4 +177,40 @@ mod tests {
             "expected {expected_apy} != actual {pool_apy}"
         );
     }
+
+    #[test]
+    fn test_zero_sats_rejected() {
+        let start = PoolSnapshot::dummy(1000, 0, 100); // zero sats
+        let end = PoolSnapshot::dummy(2000, 100, 100);
+        let result = PoolPeriod::new(start, end);
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_zero_token_amount_rejected() {
+        let start = PoolSnapshot::dummy(1000, 100, 0); // zero token_amount
+        let end = PoolSnapshot::dummy(2000, 100, 100);
+        let result = PoolPeriod::new(start, end);
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_large_k_no_overflow() {
+        // Values that would overflow u64 if multiplied directly
+        // 10^10 * 10^10 = 10^20 > u64::MAX (~1.8 * 10^19)
+        let start = PoolSnapshot::dummy(1000, 10_000_000_000, 10_000_000_000);
+        let end = PoolSnapshot::dummy(2000, 10_000_000_000, 10_000_000_000);
+        let result = PoolPeriod::new(start, end);
+        assert!(result.is_ok(), "Should handle large values without overflow");
+    }
+
+    #[test]
+    fn test_yield_calculation_valid() {
+        let start = PoolSnapshot::dummy(1000, 1000, 1000);
+        let end = PoolSnapshot::dummy(2000, 1100, 1100); // 10% increase each
+        let period = PoolPeriod::new(start, end).unwrap();
+        let yield_result = period.pool_yield().unwrap();
+        // sqrt(1.1 * 1.1) - 1 = 1.1 - 1 = 0.1 = 10%
+        assert!((yield_result - dec!(10)).abs() < dec!(0.01));
+    }
 }