Hello,

I made a withdrawal of bitcoins from coinpayu on 30 may 2019 to my blockchain wallet, but the transaction is still unconfirmed (0 confirmations). I decided to learn more about unconfirmed transactions and I am sharing with you what I learned.

Once you send bitcoins, your transaction is going to "memory pool" (mempool) which is not, unfortunately, a queue. The pool unites all the nodes connected to the bitcoin network via Bitcoin mining software. But for a transaction to be confirmed and thus a payment to be processed, a miner should pick it from the mempool and make its confirmation. 

Great, but a miner is not going to pick your transaction in a snap if its fees are small. Miners are motivated to pick transactions with the highest mining fees.

If the size of the mempool is increasing and increasing to occupy the hole RAM of a given node, the node is able to discard all those transactions with lower fees. 

Those days, the size of the mempool is bigger and bigger due to the good price of BTC and the huge number of transactions being processed and this is driving the fees through the roof. So, if your transaction is sent with ridiculous fees, YOU HAVE TO WAIT.

To have an idea about fees, have a look at this site : https://bitcoinfees.earn.com/

For a live updating of the unconfirmed bitcoin transaction : https://www.blockchain.com/en/btc/unconfirmed-transactions

Good luck with your unconfirmed transactions.

Talk to you soon.