Is it possible to send invalid transaction in mempool?

[sansahu92]

Can I broadcast a transaction without having ant bitcoin in my wallet? Like if I have an address and I want to broadcast a transaction worth 3 bitcoins. Can I do it if yes then how??

[talkbitcoin]

you can send but the nodes that receive your invalid transaction will first validate it before adding it to their mempool and when they see it is an invalid transaction they will simply reject it and don't include it in their mempool.

[sansahu92]

so if a transaction shows in mempool is valid transaction its not invalid?

[talkbitcoin]

so if a transaction shows in mempool is valid transaction its not invalid?

well first you have to know that mempool is not a singular place. it is the memory of each node. and each node is responsible for what they put in it. so a node can decide to place invalid transactions in its "memory pool" but generally speaking if a transaction is in nodes' mempool it should be a valid one because they all validate them first.

[Thirdspace]

so if a transaction shows in mempool is valid transaction its not invalid?

not always...
valid in your local mempool doesn't guarantee its validity in the network or in other nodes' mempools
so you can broadcast your 'valid transaction' based on outdated local copy of blockchain
but the whole network may reject it if the transaction was found invalid based on the latest updated blockchain