Swordfish

Swordfish is a free-to-play item on the OSRS Grand Exchange in the weapons category.

In-game examine text: "I'd better be careful eating this!"

It has a Grand Exchange buy limit of 6,000 every four hours, a high alchemy value of 48 gp, and item ID 373.

View on OSRS Wiki

Swordfish shows an active flip setup with a margin of +3 gp and 640,644 trades over the last 24 hours.

At the buy limit of 6,000 every four hours, max profit per cycle is about 18.0k gp — high margin with healthy liquidity.