Bitcoin Forum

For various reasons, I'm interested in statistics and visualizations of unspent outputs aka UTXO in the blockchain. After some googling and research on this forum, I found that I wasn't the only one (example (https://bitcointalk.org/index.php?topic=229744.0)). I think indeed that there is a lot of useful information that could be extrapolated about Bitcoin usage patterns, using this kind of bottom-up approach.

Things could get really interesting if the stats and visualizations weren't only a snapshot at given time, but a series of them at regular (meaningful) intervals, watching the evolution as the coins are moving across time.

The closest thing that I found so far is Tim Swanson's article (http://www.coindesk.com/what-block-chain-analysis-tells-bitcoin/) on CoinDesk (also on his blog (http://www.ofnumbers.com/2014/05/17/visualizing-utxo-patterns-on-the-blockchain/)). It's a very interesting read for sure, and the animation (YouTube video) is very nice. Unfortunately, as you would expect from any article, it's not an "active" dataset, i.e. the visualizations aren't updated with new data.

As an experiment, I started building a dataset myself, extracting all unspent outputs from the blockchain. The first thing that I noticed while doing this is the massive amount of generated coins that were never spent at the beginning of the chain (i.e. 2009 + early 2010). It would be interesting to postulate that these coins will actually never be spent, and to watch for any movement to confirm or invalidate that assumption.

Value of generated coins that are unspent as of March 18, 2015 (block height 348050)

Generation Year	Total Value
2009	1,078,402
2010	668,450
2011	58,345
2012	17,171
2013	19,362
2014	30,315
2015	45,252

Besides the special case of early generated coins, IMHO these statistics could greatly help analyze what I'd call cold coins:

• First criteria would be the age of unspent outputs
• Assuming P2PKH, another criteria of last activity for that pubkey can be added into the equation

Here's a screenshot from my work in progress (just a quick sheet in Numbers for now)

https://i.imgur.com/eFbuuor.png

Unfortunately my dataset isn't perfectly accurate, I guess this is caused by the lack of support for P2SH in my extraction script. As a result, the grand total of all unspent outputs in my set is 14,021,913BTC while the actual total should be about 13,950,650BTC. However, IMO this shouldn't affect the overall relevance of the stats too much.

So, the purpose of this post could also be the tl;dr:

• How much interest is there for this kind of statistics and visualizations?
• Are you aware of any existing, active project for this, as I don't want to reinvent the wheel?
• What interpretations, if any, do you think can be done from this? (e.g. computing some kind of "adjusted" market cap)
• How would you represent the evolution of these stats across time (e.g. like the animation in Tim Swanson's article (http://www.coindesk.com/what-block-chain-analysis-tells-bitcoin/))

Thanks for your feedback :)

Change over time is interesting, e.g.

http://bitcoin.sipa.be/pruning-tx.png

http://bitcoin.sipa.be/pruning-txout.png

http://bitcoin.sipa.be/pruning-size.png

Interesting graphs, especially for the divergence between pruned and all. Thanks!

Any chance of getting these plotted on a linear scale, and/or maybe the pruned vs all ratio?

 13,951,264.80231183BTC to be precise (as of block #348050) :)
Analyzing the blockchain is fun.

Interesting, I was approximating from blockchain.info but your reply puzzled me: knowing that generated coins come as 50BTC, then 25BTC per block, how could you possibly have a total that is not a multiple of 25?

I would expect the total bitcoins in circulation as of block #348050 to be exactly this:

210000 * 50 + (348050-210000) * 25 = 13,941,250BTC

So, where does your extra 14.80231183BTC come from ???


Oh yes it is, at least for us ;)

First of all there are extra 50BTC from the genesis block (however, as I know, these coins are not spendable).
The second part is more interesting. There are many blocks which has a reward less than 25 or 50BTC. Here's a couple of examples:

Look at the block #162705: https://blockchain.info/block/000000000000007dac86ae0400f08bbcac5e9e2b44bfcebb95ebda52d07f7df6
Output from the generating transaction is 50BTC, but there are fees from other transactions. Why did the miner decide not to grab them is a mistery. But the fact is that miner can lower his own reward as he wants.

Block #124724 was discussed earlier here: https://bitcointalk.org/index.php?topic=45527.0

Ahah, the devil is in the detail ;D

That makes perfect sense, thanks.