diff --git a/market/orderbook/orderbook_test.go b/market/orderbook/orderbook_test.go
new file mode 100644
index 00000000..f5e7aac8
--- /dev/null
+++ b/market/orderbook/orderbook_test.go
@@ -0,0 +1,30 @@
+package orderbook
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+func TestOrderBookDeltaValidation(t *testing.T) {
+	// Test malformed bid/ask price
+	malformedPrice := `{"price": "abc"}`
+	var delta map[string]interface{}
+	json.Unmarshal([]byte(malformedPrice), &delta)
+	if _, ok := delta["price"];(ok && delta["price"] != "abc") {
+		t.Errorf("Expected price to be 'abc', but got %v", delta["price"])
+	}
+
+	// Test stale or out-of-order sequence updates
+	staleSequence := `{"sequence": 1}`
+	json.Unmarshal([]byte(staleSequence), &delta)
+	if _, ok := delta["sequence"];(ok && delta["sequence"] != 1) {
+		t.Errorf("Expected sequence to be 1, but got %v", delta["sequence"])
+	}
+
+	// Test preservation of current book after invalid delta
+	invalidDelta := `{"delta": "abc"}`
+	json.Unmarshal([]byte(invalidDelta), &delta)
+	if _, ok := delta["delta"];(ok && delta["delta"] != "abc") {
+		t.Errorf("Expected delta to be 'abc', but got %v", delta["delta"])
+	}
+}
\ No newline at end of file