aapy: higher weight for larger pools

src/rpc/apy/apyaggregator.rs

@@ -16,22 +16,28 @@ impl APYAggregator {
         I: Iterator<Item = PoolPeriod>,
     {
         let mut weighted_apy_sum = Decimal::ZERO;
-        let mut total_active_time = Decimal::ZERO;
+        let mut total_weight = Decimal::ZERO;
 
         for pool in pools {
             let days_active = pool.duration_days(&period_start)?;
 
             if !days_active.is_zero() {
                 let (_pool_yield, apy) = pool.yield_and_apy(&period_start)?;
-                weighted_apy_sum += apy * days_active;
-                total_active_time += days_active;
+
+                // we give larger pools more weight in the aggregated apy. They have more liquidity,
+                // so the aggregated number will be more accurate.
+                let pool_size = pool.end_k_sqrt()?;
+                let weighted_apy = apy * days_active * pool_size;
+
+                weighted_apy_sum += weighted_apy;
+                total_weight += days_active * pool_size;
             }
         }
 
-        if total_active_time.is_zero() {
+        if total_weight.is_zero() {
             Ok(Decimal::ZERO)
         } else {
-            Ok(weighted_apy_sum / total_active_time)
+            Ok(weighted_apy_sum / total_weight)
         }
     }
 }

src/rpc/apy/poolperiod.rs

@@ -77,6 +77,10 @@ impl PoolPeriod {
             .unwrap_or_default())
     }
 
+    pub fn end_k_sqrt(&self) -> Result<Decimal> {
+        self.end_k.sqrt().context("failed to sqrt end")
+    }
+
     pub fn pool_yield(&self) -> Result<Decimal> {
         let start_k_sr = self.start_k.sqrt().context("failed to sqrt start")?;
         let end_k_sr = self.end_k.sqrt().context("failed to sqrt end")?;