Transaction	Amount	Received Time	Included In Blocks
TX1A	afc31... kraken to 12ngg...	0.09481172 BTC	2018-08-09 15:47:54	535949 ( 2018-08-09 16:05:30 + 18 minutes )
TX1B	17fa9... 12ngg... to 36ii5...	0.09471172 BTC	2018-08-09 15:55:31	535949 ( 2018-08-09 16:05:30 + 10 minutes )
TX2	f1c52... kraken to 12ngg...	0.62574 BTC	2018-08-09 16:04:46	535949 ( 2018-08-09 16:05:30 + 1 minutes )
TX1C	48e9d... 36ii5... collected	by coinbase	2018-08-09 16:07:12	535950 ( 2018-08-09 16:08:32 + 1 minutes )

this is just my little tx forensic, may or may not be correct
as you can see above, both transactions TX1A & TX1B was confirmed in a single block 535949
TX1B is moving an unconfirmed utxo (at that time) and using a default txfee of 10k satoshi
it's unlikey done by coinbase (like TX1C), or any exchange or online wallet
exchanges would wait for at least 1 confirmation before moving fund