diff --git a/packages/scraper/src/scrapers/market-intelligence.ts b/packages/scraper/src/scrapers/market-intelligence.ts
index 3e67c06..1972c2d 100644
--- a/packages/scraper/src/scrapers/market-intelligence.ts
+++ b/packages/scraper/src/scrapers/market-intelligence.ts
@@ -279,6 +279,9 @@ export async function computeReorderSignals(): Promise<void> {
 
     if (reasons.length === 0) reasons.push("Insufficient data for strong signal");
 
+    // Keep exactly one (latest) signal per transceiver — delete prior rows first.
+    // Without this the table grew to 4.5M rows (24h-TTL never cleaned up old runs).
+    await pool.query(`DELETE FROM reorder_signals WHERE transceiver_id = $1`, [row.id]);
     await pool.query(
       `INSERT INTO reorder_signals
          (transceiver_id, signal, signal_strength, reasons, stock_trend, price_trend, lead_time_weeks)