diff --git a/cameleer-server-app/src/test/java/com/cameleer/server/app/alerting/eval/ExchangeMatchEvaluatorTest.java b/cameleer-server-app/src/test/java/com/cameleer/server/app/alerting/eval/ExchangeMatchEvaluatorTest.java
index 7d7e696c..22308e77 100644
--- a/cameleer-server-app/src/test/java/com/cameleer/server/app/alerting/eval/ExchangeMatchEvaluatorTest.java
+++ b/cameleer-server-app/src/test/java/com/cameleer/server/app/alerting/eval/ExchangeMatchEvaluatorTest.java
@@ -5,11 +5,13 @@ import com.cameleer.server.core.alerting.*;
 import com.cameleer.server.core.runtime.Environment;
 import com.cameleer.server.core.runtime.EnvironmentRepository;
 import com.cameleer.server.core.search.ExecutionSummary;
+import com.cameleer.server.core.search.SearchRequest;
 import com.cameleer.server.core.search.SearchResult;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.mockito.ArgumentCaptor;
 
+import java.time.Duration;
 import java.time.Instant;
 import java.util.List;
 import java.util.Map;
@@ -45,10 +47,21 @@ class ExchangeMatchEvaluatorTest {
     }
 
     private AlertRule ruleWith(AlertCondition condition, Map<String, Object> evalState) {
+        return ruleWith(condition, evalState, null);
+    }
+
+    private AlertRule ruleWith(AlertCondition condition, Map<String, Object> evalState, Instant createdAt) {
         return new AlertRule(RULE_ID, ENV_ID, "test", null,
                 AlertSeverity.WARNING, true, condition.kind(), condition,
                 60, 0, 0, null, null, List.of(), List.of(),
-                null, null, null, evalState, null, null, null, null);
+                null, null, null, evalState, createdAt, null, null, null);
+    }
+
+    private ExchangeMatchCondition perExchangeCondition() {
+        return new ExchangeMatchCondition(
+                new AlertScope("orders", null, null),
+                new ExchangeMatchCondition.ExchangeFilter("FAILED", Map.of()),
+                FireMode.PER_EXCHANGE, null, null, 60);
     }
 
     private ExecutionSummary summary(String id, Instant startTime, String status) {
@@ -197,6 +210,59 @@ class ExchangeMatchEvaluatorTest {
         assertThat(captor.getValue().timeFrom()).isEqualTo(cursor);
     }
 
+    @Test
+    void cursorMonotonicity_sameMillisecondExchanges_fireExactlyOncePerTick() {
+        var t = Instant.parse("2026-04-22T10:00:00Z");
+        var exA = summary("exec-a", t, "FAILED");
+        var exB = summary("exec-b", t, "FAILED");
+        when(searchIndex.search(any())).thenReturn(new SearchResult<>(List.of(exA, exB), 2L, 0, 50));
+
+        ExchangeMatchCondition condition = perExchangeCondition();
+        AlertRule rule = ruleWith(condition, Map.of()).withEvalState(Map.of()); // first-run
+        EvalResult r1 = eval.evaluate(condition, rule,
+                new EvalContext("default", t.plusSeconds(1), new TickCache()));
+
+        assertThat(r1).isInstanceOf(EvalResult.Batch.class);
+        var batch1 = (EvalResult.Batch) r1;
+        assertThat(batch1.firings()).hasSize(2);
+        assertThat(batch1.nextEvalState()).containsKey("lastExchangeCursor");
+        // cursor is (t, "exec-b") since "exec-b" > "exec-a" lexicographically
+
+        // Tick 2: reflect the advanced cursor back; expect zero firings
+        AlertRule advanced = rule.withEvalState(batch1.nextEvalState());
+        when(searchIndex.search(any())).thenReturn(new SearchResult<>(List.of(), 0L, 0, 50));
+        EvalResult r2 = eval.evaluate(condition, advanced,
+                new EvalContext("default", t.plusSeconds(2), new TickCache()));
+        assertThat(((EvalResult.Batch) r2).firings()).isEmpty();
+
+        // Tick 3: a third exchange at the same t with exec-c > exec-b; expect exactly one firing
+        var exC = summary("exec-c", t, "FAILED");
+        when(searchIndex.search(any())).thenReturn(new SearchResult<>(List.of(exC), 1L, 0, 50));
+        EvalResult r3 = eval.evaluate(condition, advanced,
+                new EvalContext("default", t.plusSeconds(3), new TickCache()));
+        assertThat(((EvalResult.Batch) r3).firings()).hasSize(1);
+    }
+
+    @Test
+    void firstRun_boundedByRuleCreatedAt_notRetentionHistory() {
+        var created = Instant.parse("2026-04-22T09:00:00Z");
+        var after   = created.plus(Duration.ofMinutes(30));
+
+        // The evaluator must pass `timeFrom = created` to the search.
+        ArgumentCaptor<SearchRequest> cap = ArgumentCaptor.forClass(SearchRequest.class);
+        when(searchIndex.search(cap.capture())).thenReturn(
+                new SearchResult<>(List.of(summary("exec-after", after, "FAILED")), 1L, 0, 50));
+
+        ExchangeMatchCondition condition = perExchangeCondition();
+        AlertRule rule = ruleWith(condition, Map.of(), created).withEvalState(Map.of()); // no cursor
+        EvalResult r = eval.evaluate(condition, rule,
+                new EvalContext("default", after.plusSeconds(10), new TickCache()));
+
+        SearchRequest req = cap.getValue();
+        assertThat(req.timeFrom()).isEqualTo(created);
+        assertThat(((EvalResult.Batch) r).firings()).hasSize(1);
+    }
+
     @Test
     void kindIsExchangeMatch() {
         assertThat(eval.kind()).isEqualTo(ConditionKind.EXCHANGE_MATCH);