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+## cross-trading arbitrage like sandwich
+
+<br>
+
+### tl; dr
+
+- a sandwich arbitrage has characters as below:
+  - in the same block, the attacker's transactions contain a start transaction, an end transaction, and one or more victim transactions in between
+  - the combination of attacker and victim needs to satisfy an essential condition: the from address is not the same
+
+
+- the `CombinedTransferTable` of each transaction contains the same Address processing the Trade. Combining the Attacker's Start Transaction and End Transaction give the CombinedTransferTable of this arbitrage having the final net surplus.
+
+
+<br>