diff --git a/src/analytics/performance.zig b/src/analytics/performance.zig
index 619c96e..71672fd 100644
--- a/src/analytics/performance.zig
+++ b/src/analytics/performance.zig
@@ -30,9 +30,9 @@ pub const PerformanceResult = struct {
 
 /// Compute total return from adjusted close prices.
 /// Candles must be sorted by date ascending.
-/// `from` snaps forward (first trading day on/after), `to` snaps backward.
+/// `from` snaps backward (last trading day on/before), `to` snaps backward.
 pub fn totalReturnFromAdjClose(candles: []const Candle, from: Date, to: Date) ?PerformanceResult {
-    return totalReturnFromAdjCloseSnap(candles, from, to, .forward);
+    return totalReturnFromAdjCloseSnap(candles, from, to, .backward);
 }
 
 /// Same as totalReturnFromAdjClose but both dates snap backward
@@ -253,13 +253,14 @@ fn findNearestCandle(candles: []const Candle, target: Date, direction: SearchDir
     const candidate = switch (direction) {
         // First candle on or after target
         .forward => if (lo < candles.len) candles[lo] else return null,
-        // Last candle on or before target
+        // Last candle on or before target; if target is before all data,
+        // fall back to first candle (snap distance check will reject if too far)
         .backward => if (lo < candles.len and candles[lo].date.eql(target))
             candles[lo]
         else if (lo > 0)
             candles[lo - 1]
         else
-            return null,
+            candles[0],
     };
 
     // Reject if the snap distance exceeds tolerance