3.13 Lightning Liquidity: Inbound vs Outbound

Every Lightning channel has two sides: your side (called outbound — coins ready for you to send) and the other party's side (inbound — capacity available for someone to send to you).

Brand new channels start unbalanced. If you fund a channel with $100, all $100 is outbound — you can send $100 but can't receive a cent until someone pays you and moves balance to the other side.

There are several ways to fix this: ask someone to send a small Lightning payment to you (moves outbound→inbound), use a swap service like Loop or Boltz to convert on-chain coins into inbound capacity, or buy inbound capacity from a Liquidity Service Provider.

If you run a routing node (one that helps move other people's payments), liquidity management becomes a real craft. You set fees on each channel, pick well-connected peers, and rebalance regularly to keep both sides usable. Done well, your node earns routing fees that turn idle capital into yield.