<p>I am not sure if it is possible to give a satisfying / definite answer to your question. As far as I can tell lightning developers have been very cautious in the early days (and still are) with everything that might make people loose funds. Negative fees are an obvious possibility to loose money as people would route along that channel and you would have to pay for that if you don't actively manage your node and know what you do.</p>
<p>On a bit more opinionated level and from a mathematical point of view I agree that it is a little bit strange that the cost function is just not permitted to have negative values and I agree that a lot of things with respect to liquidity management, routing and payments would probably be much easier if we did not have to make that somewhat artificial distinction.</p>

CC BY-SA 4.0
2021-09-20T16:04:20.703Z
2021-09-20T16:04:20.703Z
Rene Pickhardt
<p>Negative fees would create the problem of finding the shortest (cheapest) path in the network, since a fast algorithm to find the shortest path in negative-weight graphs was elusive.</p>
<p>Not anymore:</p>
<p><a href="https://www.quantamagazine.org/finally-a-fast-algorithm-for-shortest-paths-on-negative-graphs-20230118" rel="nofollow noreferrer">https://www.quantamagazine.org/finally-a-fast-algorithm-for-shortest-paths-on-negative-graphs-20230118</a></p>

CC BY-SA 4.0
2023-01-19T20:11:03.580Z
2023-01-19T20:11:03.580Z
bordalix
<p>Adding on a little later, here. There was some discussion on <a href="https://twitter.com/bitcoin_eagle/status/1540286208554766338?t=C8ruLhEzeNJGlFdFsRzVww&amp;s=19" rel="nofollow noreferrer">Twitter</a> about this, regarding nodes used for the purpose of surveillance. Better statistical on-chain data can be obtained by processing more transactions which negative fees would encourage. So, based on my limited understanding, a negative fee could incentivize the monetization of users' on-chain activity records.</p>

CC BY-SA 4.0
2022-06-25T13:07:55.970Z
2022-06-25T13:07:55.970Z
fuzzybear3965
<p>Why there aren't negative fees on lightning network protocol and the ability to set incoming fees? Would there be any benefit? Let me describe the situation. There are nodes where the most of the liquidity goes to (the terminal type) and the nodes where the most of the liquidity goes from (the initial type). To rebalance it back is sometimes costly. A lightning node operator would maybe be willing to pay people to send satoshis from certain terminal nodes (setting incoming fees on negative) and send them to the initial type nodes (setting outcoming fees on negative).</p>

CC BY-SA 4.0
2023-01-19T21:47:12.603Z
Inbound Fees is a proposal currently discussed in the Lightning world, so it may become a possibility in the future. For a recent status see this thread: https://twitter.com/lucasdcf/status/1615413064148328448
OptOut
<lightning-network><lightning-fees>
Negative fees on Lightning network and fees on incoming liquidity
Jan Siebert
# Negative fees on Lightning network and fees on incoming liquidity

(Asked by: username_0 on 2021-09-20)

Why there aren't negative fees on lightning network protocol and the ability to set incoming fees? Would there be any benefit? Let me describe the situation. There are nodes where the most of the liquidity goes to (the terminal type) and the nodes where the most of the liquidity goes from (the initial type). To rebalance it back is sometimes costly. A lightning node operator would maybe be willing to pay people to send satoshis from certain terminal nodes (setting incoming fees on negative) and send them to the initial type nodes (setting outcoming fees on negative).

**Tags:** lightning-network, lightning-fees

> **Comments:**
> **username_1**: Inbound Fees is a proposal currently discussed in the Lightning world, so it may become a possibility in the future. For a recent status see this thread: https://twitter.com/lucasdcf/status/1615413064148328448  

---

## 3 answers

### Answer by username_2 on 2021-09-20. Score: 3

I am not sure if it is possible to give a satisfying / definite answer to your question. As far as I can tell lightning developers have been very cautious in the early days (and still are) with everything that might make people loose funds. Negative fees are an obvious possibility to loose money as people would route along that channel and you would have to pay for that if you don't actively manage your node and know what you do.

On a bit more opinionated level and from a mathematical point of view I agree that it is a little bit strange that the cost function is just not permitted to have negative values and I agree that a lot of things with respect to liquidity management, routing and payments would probably be much easier if we did not have to make that somewhat artificial distinction.


---

### Answer by username_3 on 2023-01-19. Score: 0

Negative fees would create the problem of finding the shortest (cheapest) path in the network, since a fast algorithm to find the shortest path in negative-weight graphs was elusive.

Not anymore:

<https://www.quantamagazine.org/finally-a-fast-algorithm-for-shortest-paths-on-negative-graphs-20230118>


---

### Answer by username_4 on 2022-06-25. Score: 0

Adding on a little later, here. There was some discussion on [Twitter](https://twitter.com/bitcoin_eagle/status/1540286208554766338?t=C8ruLhEzeNJGlFdFsRzVww&s=19) about this, regarding nodes used for the purpose of surveillance. Better statistical on-chain data can be obtained by processing more transactions which negative fees would encourage. So, based on my limited understanding, a negative fee could incentivize the monetization of users' on-chain activity records.


---

