<p>For the largest part of 2016 we saw rising fee levels. This seemed to bode that a large number of low-value UTXOs would soon become economically unspendable due to their value being outpaced by the cost of creating a transaction input to spend them.</p>

<ol>
<li>This has strongly discouraged people from creating small outputs.</li>
<li>Use cases entailing microtransactions had reduced volume.</li>
<li>Some large companies have taken notice and started consolidating funds.</li>
<li>Fees hurt enough that wallet developers and companies invested in some coin selection improvements. </li>
</ol>

<hr>

<p><sup>After writing this I notice that my answer is pretty much echoing alcio's. Kudos to him, his answer came first.</sup></p>

CC BY-SA 3.0
2017-07-12T04:50:40.020Z
2017-07-12T04:50:40.020Z
Murch
<p>The number of unconfirmed transactions lowered (due to significant growing hashrate) and miners ready to confirm low-priority transactions where inputs count is more than output count.</p>

<p>For example, take this block <a href="https://blockchain.info/block/0000000000000000003058a04965c989c929352002b792f83c7274247e15eca7" rel="nofollow noreferrer">https://blockchain.info/block/0000000000000000003058a04965c989c929352002b792f83c7274247e15eca7</a> and scroll to the bottom. You will see transactions which combine small inputs. Such combining has the reason when done with small fees</p>

<p>So, the number of UTXO lowers (or grows slower) when the network is not busy</p>

CC BY-SA 3.0
2017-07-12T05:51:01.100Z
2017-07-12T06:01:57.240Z
2017-07-12T06:01:57.240Z
amaclin
<p>My guess, is that it's a consolidation of a lot of 0-small fee transactions that just built up for a long time.  Once the mempool emptied, then all the dust got cleaned up into fewer transactions outputs.</p>

CC BY-SA 3.0
2017-07-12T08:47:02.950Z
2017-07-12T08:47:02.950Z
Mr.Nobody
<p>Currently its cheaper to create TX's that increase the set, so there was a lot of incentive for wallet to create dust. After Segwit, it's not cheaper anymore if you increase the set.</p>

<p>So my guess is that a lot of wallets already updated their TX creation algorithms for Segwit.</p>

CC BY-SA 3.0
2017-07-11T12:23:07.937Z
Are you saying it is cheaper to do X than to do Y? If so, can you clarify in your answer, what is the X and what is the Y?
Peter
CC BY-SA 3.0
2017-07-11T12:32:22.123Z
It's cheaper to create an output (increasing the UTXO set size) than consuming it (reducing the UXTO set size). Segwit fixes that misaligned incentive by making it roughly the same cost. However, I don't think wallets adapted their tx creation algorithm for SW yet, as it is not active.
alcio
CC BY-SA 3.0
2017-07-14T03:01:35.690Z
@alcio: It's still about two times as expensive with segwit to consume a UTXO vs creating one. Much better, but by no means "fixed", unfortunately.
Murch
CC BY-SA 3.0
2017-07-11T11:20:35.687Z
2017-07-11T11:20:35.687Z
Maestro
<p>It's hard to know for sure what's been going on. My guess would be it's a mix of :</p>

<ul>
<li>Better coin selection algorithms used by large wallets (exchanges)</li>
<li>Increase in fees pushed some inefficient services to stop creating uneconomical outputs (low values). Those services would be gambling/faucets/etc.. They might now be forcing withdrawals to be above a given amount</li>
<li>Some services consolidating their wallets since fees have lowered a bit from the last few weeks.</li>
</ul>

CC BY-SA 3.0
2017-07-11T12:30:41.527Z
2017-07-12T08:44:24.733Z
2017-07-12T08:44:24.733Z
alcio
<p>The bitcoin UTXO set appears to have stopped growing on 2017-06-3 after 5 or more years of nearly constant increase. What are the reasons (or hypotheses) why?</p>

<p>Charts below:</p>

<ul>
<li>2012 to 2017-07-11 <a href="https://blockchain.info/charts/utxo-count?timespan=all" rel="noreferrer">https://blockchain.info/charts/utxo-count?timespan=all</a></li>
<li>60 days to 2017-07-11 <a href="https://blockchain.info/charts/utxo-count?timespan=all" rel="noreferrer">https://blockchain.info/charts/utxo-count?timespan=all</a></li>
</ul>

<p><a href="https://i.sstatic.net/zQmzq.png" rel="noreferrer"><img src="https://i.sstatic.net/zQmzq.png" alt="screenshots of charts"></a></p>

<transactions><utxo>
Why has UTXO set stopped growing since 2017-06-03?
Peter
# Why has UTXO set stopped growing since 2017-06-03?

(Asked by: username_0 on 2017-07-11)

The bitcoin UTXO set appears to have stopped growing on 2017-06-3 after 5 or more years of nearly constant increase. What are the reasons (or hypotheses) why?

Charts below:

* 2012 to 2017-07-11 <https://blockchain.info/charts/utxo-count?timespan=all>
* 60 days to 2017-07-11 <https://blockchain.info/charts/utxo-count?timespan=all>

[![screenshots of charts](https://i.sstatic.net/zQmzq.png)](https://i.sstatic.net/zQmzq.png)

**Tags:** transactions, utxo


---

## 5 answers

### Answer by username_5 on 2017-07-11. Score: 6 | Accepted answer

It's hard to know for sure what's been going on. My guess would be it's a mix of :

* Better coin selection algorithms used by large wallets (exchanges)
* Increase in fees pushed some inefficient services to stop creating uneconomical outputs (low values). Those services would be gambling/faucets/etc.. They might now be forcing withdrawals to be above a given amount
* Some services consolidating their wallets since fees have lowered a bit from the last few weeks.


---

### Answer by username_1 on 2017-07-12. Score: 1

For the largest part of 2016 we saw rising fee levels. This seemed to bode that a large number of low-value UTXOs would soon become economically unspendable due to their value being outpaced by the cost of creating a transaction input to spend them.

1. This has strongly discouraged people from creating small outputs.
2. Use cases entailing microtransactions had reduced volume.
3. Some large companies have taken notice and started consolidating funds.
4. Fees hurt enough that wallet developers and companies invested in some coin selection improvements.

---

After writing this I notice that my answer is pretty much echoing username_5's. Kudos to him, his answer came first.


---

### Answer by username_2 on 2017-07-12. Score: 0

The number of unconfirmed transactions lowered (due to significant growing hashrate) and miners ready to confirm low-priority transactions where inputs count is more than output count.

For example, take this block <https://blockchain.info/block/0000000000000000003058a04965c989c929352002b792f83c7274247e15eca7> and scroll to the bottom. You will see transactions which combine small inputs. Such combining has the reason when done with small fees

So, the number of UTXO lowers (or grows slower) when the network is not busy


---

### Answer by username_3 on 2017-07-12. Score: 0

My guess, is that it's a consolidation of a lot of 0-small fee transactions that just built up for a long time. Once the mempool emptied, then all the dust got cleaned up into fewer transactions outputs.


---

### Answer by username_4 on 2017-07-11. Score: 0

Currently its cheaper to create TX's that increase the set, so there was a lot of incentive for wallet to create dust. After Segwit, it's not cheaper anymore if you increase the set.

So my guess is that a lot of wallets already updated their TX creation algorithms for Segwit.

> **Comments:**
> **username_0**: Are you saying it is cheaper to do X than to do Y? If so, can you clarify in your answer, what is the X and what is the Y?  
> **username_5**: It's cheaper to create an output (increasing the UTXO set size) than consuming it (reducing the UXTO set size). Segwit fixes that misaligned incentive by making it roughly the same cost. However, I don't think wallets adapted their tx creation algorithm for SW yet, as it is not active.  
> **username_1**: @username_5: It's still about two times as expensive with segwit to consume a UTXO vs creating one. Much better, but by no means "fixed", unfortunately.  

---

