Hello,

Looking for an explanation for something like the following:

Block: #515266

Output: 99,681.95307254 BTC

Link: https://blockchain.info/block-index/1684356

So if you look through the transactions, there are multiple transactions for about 6,300 BTC being sent around from a wallet with ID 17A16QmavnUfCW11DAApiJxp7ARnxN5pGX (https://blockchain.info/address/17A16QmavnUfCW11DAApiJxp7ARnxN5pGX) .

I'm a little confused because it appears that the wallet was able to send itself the same BTC holdings multiple times (multiple transactions) within the same block. The wallet name relates to Poloniex, but it only has a balance of about 6.3k BTC. If you look at the transactions within the block, it was able to circulate that balance multiple times.

My understanding was that if you own 6.3k BTC and you send the full balance to yourself, the 6.3k BTC goes into processing until the transaction is confirmed, meaning that you are not able to put through a second transaction with the balance until it circles back around to you. However, this wallet was able to put through multiple transactions that utilized the full balance within one block.

I'm wondering if this is double spending or if my understanding is missing something?

In advance, thank you for taking the time to read this and for your responses.