Believe it or not, Bitcoin isn't actually transactional these days. A new feature called "replace by fee" was introduced that allows coins that were used in a

Believe it or not, Bitcoin isn't actually transactional these days. A new feature called "replace by fee" was introduced that allows coins that were used in a transaction which is still in queue for processing (hasn't yet been included in block by the miners) to be spent in a different transaction as long as the spender pays a high enough fee to jump to the front of the queue.