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This week, the movement of 50 old bitcoins has received a lot of attention. Meanwhile, @ziggamon was staring at the mempool... https://twitter.com/ziggamon/status/1264233417362878466?s=20">https://twitter.com/ziggamon/...
A short discussion with him convinced me to check the case. That seemed like an easy one. God, I didn& #39;t know the monster that he was observing.
First step was to get a better picture of what was happening by clustering the addresses of this entity. To date, more than 2.3 millions of addresses have been identified but this figure is a lower bound. I suspect the real number may be as high as 4 millions of addresses.
The main characteristic of these addresses is that there are all 1-of-1 multisigs nested in P2SH or P2WPSH scripts. I will affectionately call this entity Crazy1o1 
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When he contacted me, @ziggamon suspected that Crazy1o1 was playing an important role in the congestion of the mempool. Well, he wasn& #39;t wrong. Since May 1st, Crazy1o1 has spent around 804k UTXOs. It& #39;s more than the #UTXOs usually spent per day.
In terms of fees, Crazy1o1 has paid more than 104BTC in mining fees since May 1st.https://abs.twimg.com/emoji/v2/... draggable="false" alt="😳" title="Flushed face" aria-label="Emoji: Flushed face">
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On some days, these fees are equivalent to 10-12% of all the fees received by miners.
Beyond the fact that Crazy1o1 uses 1-of-1 multisigs, we know a few things about this entity...
It has been operating since June 2019. It has slowly and patiently accumulated a large number of UTXOs.
Many of its transactions have a specific fingerprint with 3 outputs. 1 output seems to be sent to another wallet, 2 outputs are sent back to the wallet.
Lately its transactions have been consolidating a lot of UTXOs with a close denomination. It may suggests that Crazy1o1 uses an algorithm consolidating UTXOs by decreasing amounts.
Regarding others sources and destinations of funds, the analysis remains to be done but a manual inspection suggests many links with exchanges like Coinbase.
/End (for now)
