OP_MUL ​
INFO
Opcode number: 149
Byte representation: 0x95
Short description: Fail the script unconditionally, does not even need to be executed.
OP_MUL is a disabled opcode in the Bitcoin scripting system.
Historical Context ​
OP_MUL was intended to perform multiplication operations between the two topmost items on the stack.
Due to concerns about potential vulnerabilities and the desire to simplify the scripting language, OP_MUL (along with several other opcodes) was disabled early in bitcoin's development.
Operation ​
Because OP_MUL is disabled, any script that contains it will render the transaction invalid regardless of context.