diff --git a/lib/traders/ib.js b/lib/traders/ib.js
index 1694f9a3..6b3097e2 100644
--- a/lib/traders/ib.js
+++ b/lib/traders/ib.js
@@ -630,7 +630,7 @@ class MarketDepthDatum extends TraderDatum {
 
     const bookSide = side === 1 ? orderbook.bids : orderbook.asks;
 
-    if (operation === 2) {
+    if (operation === 2 || size === 0) {
       bookSide.delete(position);
     } else {
       const roundLot = this.#roundLots.get(symbol) ?? 100;