Bark

Bark is a members-only item on the OSRS Grand Exchange in the bars category.

In-game examine text: "Bark from a hollow tree."

It has a Grand Exchange buy limit of 13,000 every four hours, a high alchemy value of 1 gp, and item ID 3239.

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Bark shows an active flip setup with a margin of +31 gp and 23,828 trades over the last 24 hours.

At the buy limit of 13,000 every four hours, max profit per cycle is about 403.0k gp — high margin with healthy liquidity.