definitely is... #15 on the Richlist (actually) was the original Premine address (**see note A)

It was reorganized on July 7, when #6 on the list was created as a spinoff (starting with just ONE huge block).

#8 actually has a very similar structure (huge blocks), was as well reorganized on July 7, but the source of the coins is more complicated... but this could easily be a address of the dev as well, if he participated in mining during the bonanza - solo or via pool.

If all of them are different addresses in the same wallet, this would explain why they perform quite a bit better than average (large weight in the network - far larger inputs than average, so staking frequently - but not VERY often, but getting large rewards..) (but actually starting to fall behind as well now, with inputs getting smaller due to frequent splitting).

**note A - this Address is still used by coinmarkets-cap to calculate the difference between "total supply" and "circulating supply" - they just wanted to exclude the pre-mine from the circulating supply - but as this address is staking as well, and the amount is (due to the aforementioned reorganization) much lower than the original premine, that doesn't really make any sense anymore...