<p>I don't think your question quite makes sense. Bitcoins aren't "transmitted", they simply sit in the block chain until someone chooses to spend them. There's no way to tell if a particular Bitcoin is lost or not because that depends on whether anyone knows they key needed to claim it. That key could be written on a piece of paper for all we know.</p>

<p>When your client tells you that you have 50 Bitcoins, it is doing that in a purely passive way. Nobody can tell that your wallet contains the keys needed to claim those Bitcoins, and this is by intentional design.</p>

<p>You could fairly easily measure how many coins hadn't been spent since they were mined. But that wouldn't really tell you anything. Some of those coins may have lost keys and some may not. And some coins may have been spent once and then lost.</p>

CC BY-SA 3.0
2011-09-09T02:47:58.650Z
I just would like to have an information to speculate how many coins are "obsolete" (lost). To know this kind of information I think could exist a tool where I could filter something like: Total of coins that was not spent last year, or since the beginning of Bitcoin and so on.
Leo
CC BY-SA 3.0
2011-09-09T07:01:49.003Z
I don't think it's reasonable to infer that a coin is lost just because it hasn't been spent in a year. However, I suppose it is reasonable to infer that the longer the time since a Bitcoin was last spent, the more likely that it's lost. So a coin age histogram might give you some clue how many coins are lost. But so far as I know, there is no good information that would permit making reasonable assumptions about what percentage of coins are lost based on their age. Many people are intentionally holding coins without moving them.
David Schwartz
CC BY-SA 3.0
2011-09-09T02:39:03.613Z
2011-09-09T02:39:03.613Z
David Schwartz
<p>I don't believe anyone has compiled the information but you could obtain it all from block explorer.</p>

<p>You would need to go through block chain and record the signing destination of all 144,667 blocks.  </p>

<p>Here is an example:
<a href="http://blockexplorer.com/block/00000000000000f993d2fd712906ff1a5f79125d12f2832aa0616de1d4949e6e" rel="nofollow">http://blockexplorer.com/block/00000000000000f993d2fd712906ff1a5f79125d12f2832aa0616de1d4949e6e</a></p>

<p>These are the "original" (as of today) 144,667 blocks.  With a list of them you could simply scan the block chain to look for at least one transaction (other than signing transaction) involving that address.</p>

<p>A couple of issues:
a) like David said above just because it hasn't been spent doesn't mean it is lost (unrecoverable).  Many of the early adopters racked up hundreds of thousands of bitcoin.  Highly probable that many of them are still accessible and simply haven't been transferred.</p>

<p>b) second issue is the existence of pools.  With mining pool there will always be one transfer.  From the pool to pool member.  </p>

CC BY-SA 3.0
2011-09-09T21:11:10.793Z
a better statistic might be "length of time since last transfer", though this would require some custom programming and it is still arguable how much information one can actually infer from it.
lemonginger
CC BY-SA 3.0
2011-09-09T21:22:26.633Z
Agreed.  "lost" is an invalid assumption but one could however write software to parse the chain and provide stats like "18% of addresses had a transaction in the last year".  Like you said it may be of dubious value but it can be done.  Saying "x% of bitcoins have been lost" is simply impossible.
DeathAndTaxes
CC BY-SA 3.0
2011-09-10T15:05:11.543Z
Yes, what I mean is some easy tool to provide stats like (How many % of address had a transaction last year or month...) (What month had more or less transactions done) and so on...
Leo
CC BY-SA 3.0
2011-09-10T16:21:36.687Z
@Leo.  As far as I know that doesn't exist yet.  Should be an interesting programming project though.
DeathAndTaxes
CC BY-SA 3.0
2011-09-09T21:04:33.607Z
2011-09-09T21:04:33.607Z
DeathAndTaxes
<p>I would like to know how many BTC have not moved from the block they were mined in - never transferred or spent. (With this information I believe could have an idea of how many BTC have been lost). Is there a tool to see this kind of information?</p>

<tools>
How do we know how many BTC have not been spent since being mined? Any tool to see this information?
Leo
# How do we know how many BTC have not been spent since being mined? Any tool to see this information?

(Asked by: username_0 on 2011-09-09)

I would like to know how many BTC have not moved from the block they were mined in - never transferred or spent. (With this information I believe could have an idea of how many BTC have been lost). Is there a tool to see this kind of information?

**Tags:** tools


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## 2 answers

### Answer by username_1 on 2011-09-09. Score: 3

I don't think your question quite makes sense. Bitcoins aren't "transmitted", they simply sit in the block chain until someone chooses to spend them. There's no way to tell if a particular Bitcoin is lost or not because that depends on whether anyone knows they key needed to claim it. That key could be written on a piece of paper for all we know.

When your client tells you that you have 50 Bitcoins, it is doing that in a purely passive way. Nobody can tell that your wallet contains the keys needed to claim those Bitcoins, and this is by intentional design.

You could fairly easily measure how many coins hadn't been spent since they were mined. But that wouldn't really tell you anything. Some of those coins may have lost keys and some may not. And some coins may have been spent once and then lost.

> **Comments:**
> **username_0**: I just would like to have an information to speculate how many coins are "obsolete" (lost). To know this kind of information I think could exist a tool where I could filter something like: Total of coins that was not spent last year, or since the beginning of Bitcoin and so on.  
> **username_1**: I don't think it's reasonable to infer that a coin is lost just because it hasn't been spent in a year. However, I suppose it is reasonable to infer that the longer the time since a Bitcoin was last spent, the more likely that it's lost. So a coin age histogram might give you some clue how many coins are lost. But so far as I know, there is no good information that would permit making reasonable assumptions about what percentage of coins are lost based on their age. Many people are intentionally holding coins without moving them.  

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### Answer by username_2 on 2011-09-09. Score: 2

I don't believe anyone has compiled the information but you could obtain it all from block explorer.

You would need to go through block chain and record the signing destination of all 144,667 blocks.

Here is an example:
<http://blockexplorer.com/block/00000000000000f993d2fd712906ff1a5f79125d12f2832aa0616de1d4949e6e>

These are the "original" (as of today) 144,667 blocks. With a list of them you could simply scan the block chain to look for at least one transaction (other than signing transaction) involving that address.

A couple of issues:
a) like username_1 said above just because it hasn't been spent doesn't mean it is lost (unrecoverable). Many of the early adopters racked up hundreds of thousands of bitcoin. Highly probable that many of them are still accessible and simply haven't been transferred.

b) second issue is the existence of pools. With mining pool there will always be one transfer. From the pool to pool member.

> **Comments:**
> **username_3**: a better statistic might be "length of time since last transfer", though this would require some custom programming and it is still arguable how much information one can actually infer from it.  
> **username_2**: Agreed.  "lost" is an invalid assumption but one could however write software to parse the chain and provide stats like "18% of addresses had a transaction in the last year".  Like you said it may be of dubious value but it can be done.  Saying "x% of bitcoins have been lost" is simply impossible.  
> **username_0**: Yes, what I mean is some easy tool to provide stats like (How many % of address had a transaction last year or month...) (What month had more or less transactions done) and so on...  
> **username_2**: @username_0.  As far as I know that doesn't exist yet.  Should be an interesting programming project though.  

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