Halibut

Halibut is a members-only item on the OSRS Grand Exchange in the other category.

In-game examine text: "Some nicely cooked halibut."

It has a Grand Exchange buy limit of 10,000 every four hours, a high alchemy value of 102 gp, and item ID 32336.

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Halibut shows an active flip setup with a margin of +50 gp and 320,620 trades over the last 24 hours.

At the buy limit of 10,000 every four hours, max profit per cycle is about 500.0k gp — high margin with healthy liquidity.