Trawl

Trawl is liquidation in Bythos. When a Line's health falls below 1.00, anyone can trawl it: the collateral is sold into the venue that priced it, the debt is repaid, and the borrower keeps whatever is left.

When a Line can be trawled

A Line can be trawled when its health is below 1.00:

health = (0.85 × DV) / debt

Here DV is the live value of all collateral, min(live sounding, qty × TWAP30 × 0.9). If the pool cannot be read, live value is 0 and the Line can be trawled. See Lines.

Who trawls

Anyone. There is no whitelist and no special role. In practice, keepers watch Lines and call Trawl when health crosses below 1.00. Each successful Trawl pays the caller a keeper bonus of 3% of the debt, in HYPE. Keepers can run through the Ichor paymaster for gas.

How it sells

The main path is liquidate(market, borrower):

1. The Trawl contract seizes the Line's collateral.
2. It sells just enough of it through the Market's registered pool to raise debt × 1.05.
3. It pays the proceeds in this order:
   • 3% of the debt to the caller (keeper bonus, in HYPE)
   • the debt to the Market
   • 2% of the debt as the protocol share
4. Unsold collateral goes back to the borrower.

Trawl sells into the venue that priced the position. Sounding valued the collateral by simulating a sale into that pool, and Trawl recovers the value with a real sale into the same pool. That is why Depth Value is a useful limit: it is the amount a liquidation can actually raise.

Worked example

A Line holds 20,000 tokens with 1.26 HYPE of debt. Depth in the pool falls and live value drops to 1.45 HYPE. Health is (0.85 × 1.45) / 1.26 ≈ 0.98, below 1.00.

A keeper calls liquidate. Trawl sells enough tokens to raise 1.26 × 1.05 = 1.323 HYPE:

Recipient	Share	Amount
Keeper	3% of debt	0.0378 HYPE
Market (lenders)	the debt	1.26 HYPE
Protocol	2% of debt	0.0252 HYPE
Total	debt × 1.05	1.323 HYPE

On testnet, the 0.0252 HYPE protocol share is split half to the Market's Abyss Reserve (0.0126 HYPE) and half to the Treasury (0.0126 HYPE). The tokens that were not sold go back to the borrower.

When the sale is not enough

If selling all the collateral does not cover the debt, the Market is left with a shortfall. It is handled in two steps:

1. The shortfall is requested from that Market's Abyss Reserve.
2. Whatever the reserve cannot cover is written off across that Market's lenders only.

No other Market is touched. See Abyss Reserve.

When the pool cannot be read

If the pool route is unavailable, a pool sale is not possible. For that case only, Trawl offers liquidateByTransfer(market, borrower), a payable call:

1. The caller pays the Line's debt in HYPE.
2. The caller receives collateral priced at 5% below TWAP30.
3. The rest of the collateral returns to the borrower.

Example: debt is 1.26 HYPE and TWAP30 is 0.0001 HYPE per token. The transfer price is 0.0001 × 0.95 = 0.000095 HYPE per token, so the caller receives 1.26 / 0.000095 ≈ 13,263.16 tokens. Of a 20,000-token Line, about 6,736.84 tokens return to the borrower.

Fallback order

Trawl always tries the venue closest to where the position was priced:

Order	Route	Available
1	HyperCore intent, through EL1Write	Phase 1 · book sounding (after ArbOS upgrade)
2	Elysium pool swap	Phase 0 and Phase 1
3	Collateral sale to the caller at a 5% discount	When no sale route is available

The testnet build implements routes 2 and 3. Route 1 is planned for Phase 1, after the ArbOS upgrade. See Phases and roadmap.

Notes for keepers

• Health uses the live sounding, so a Line can become trawlable within a block of a depth drop.
• The bonus is 3% of the debt, not of the collateral. Small Lines pay small bonuses.
• A Trawl repays the Line's full debt. Unsold collateral is returned to the borrower, not kept by the caller.