Numulite

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

In-game examine text: "A form of currency on Fossil Island."

It has a Grand Exchange buy limit of 30,000 every four hours, a high alchemy value of 6 gp, and item ID 21555.

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Numulite shows an active flip setup with a margin of +1 gp and 3,213,971 trades over the last 24 hours.

At the buy limit of 30,000 every four hours, max profit per cycle is about 30.0k gp — high margin with healthy liquidity.